EP1140758A1

EP1140758A1 - Method for preparing a benzylic-type ether

Info

Publication number: EP1140758A1
Application number: EP00900536A
Authority: EP
Inventors: Roland Jacquot; Michel Spagnol
Original assignee: Rhodia Chimie SAS
Current assignee: Rhodia Chimie SAS
Priority date: 1999-01-08
Filing date: 2000-01-07
Publication date: 2001-10-10
Also published as: US6608232B1; HUP0104918A2; AU3051400A; WO2000040535A1; CN1341090A; FR2788269A1; IL144176A0; HUP0104918A3; JP2002534403A; FR2788269B1

Abstract

The invention concerns a method for preparing a benzylic-type ether from an aromatic compound. The inventive method for preparing a benzylic-type ether from an aromatic compound is characterised in that it consists in: in a first step, acylating an aromatic compound by reacting said aromatic compound with an acylating agent, in the presence of an efficient amount of zeolite or a Friedel-Crafts catalyst leading to a ketonic compound; in a second step, reducing the carbonyl group into carbinol leading to a benzylic alcohol; in a third step, etherifying the hydroxyl group, by reacting the benzylic alcohol with another alcohol, in the presence of an efficient amount of zeolite.

Description

PROCESS FOR THE PREPARATION OF A BENZYI IQUE ETHER.

The present invention relates to a process for the preparation of a benzyl ether from an aromatic compound.

By "benzyl type ether" is meant a compound comprising at least one aromatic carbocycle or heterocycle in which a hydrogen atom directly linked to the aromatic nucleus is replaced by an ether function.

The production of benzyl ethers is not easy on an industrial scale.

Not only are the reagents generally expensive, but side reactions are possible because the starting alcohols and the ethers obtained easily form peroxides which have a high explosive potential.

The object of the present invention is to provide a process making it possible to obtain a benzyl type ether, from an aromatic compound, making it possible to avoid the stated disadvantages.

More specifically, the subject of the present invention is a process for the preparation of a benzyl ether from an aromatic compound characterized in that it consists:

- In a first step, to carry out the acylation of an aromatic compound by reaction of said compound with an acylating agent, in the presence of an effective amount of a zeolite or of a Friedel-Crafts catalyst leading to a ketone compound,

- in a second step, to carry out the reduction of the carbonyl group to the carbinol group leading to a benzyl type alcohol, - in a third step, to effect the etherification of the hydroxyl group, by reaction of the benzyl type alcohol with a other alcohol in the presence of an effective amount of a zeolite.

According to the method of the invention, the first step is the acylation of an aromatic compound by reaction of the latter with an acylating agent.

In the following description of the present invention, the term "aromatic compound" means the conventional concept of aromaticity as defined in literature, in particular by Jerry MARCH, Advanced Organic Chemistry, 4 ^th edition, John Wiley and Sons, 1992, pp. 40 and following.

The term "acylating agent" is used generically and designates any agent allowing the connection to an aromatic cycle of a carbonyl group, and in particular benzoylating agents.

More specifically, the subject of the present invention is a process for acylating an aromatic compound corresponding to the general formula (I):

in which :

- A symbolizes the remainder of a cycle forming all or part of a carbocyclic or heterocyclic, aromatic, monocyclic or polycyclic system: said cyclic residue being able to carry a group R representing a hydrogen atom or one or more substituents, identical or different , - n represents the number of substituents on the cycle.

The invention applies in particular to aromatic compounds corresponding to formula (I) in which A is the residue of a cyclic compound, preferably having at least 4 atoms in the ring, preferably 5 or 6, optionally substituted , and representing at least one of the following cycles:. an aromatic, monocyclic or polycyclic carbocycle,

. an aromatic, monocyclic or polycyclic heterocycle comprising at least one of the heteroatoms O, N and S,

It will be specified, without however limiting the scope of the invention, that the residue A optionally substituted represents, the remainder: 1 ° - of an aromatic, monocyclic or polycyclic carbocyclic compound. By "carbocyclic polycyclic compound" means:. a compound consisting of at least 2 aromatic carbocycles and forming between them ortho- or ortho- and pericondensed systems,. a compound consisting of at least 2 carbocycles of which only one of them is aromatic and forming between them ortho- or ortho- and pericondensed systems. 2 ° - of a heterocyclic aromatic, monocyclic or polycyclic compound. By "heterocyclic poiycyclic compound", we define:. a compound consisting of at least 2 heterocycles containing at least one heteroatom in each cycle including at least one of the two cycles is aromatic and forms between them ortho- or ortho- and pericondensed systems,. a compound consisting of at least one hydrocarbon ring and at least one heterocycle of which at least one of the rings is aromatic and forming between them ortho- or ortho- and pericondensed systems.

3 ° - of a compound constituted by a chain of cycles, as defined in paragraphs 1 and / or 2 linked together:. by a valential link,

. by an alkylene or alkylidene group having from 1 to 4 carbon atoms, preferably a methylene or isopropylidene group,

. by one of the following groups:

-O-, -CO-, -COO-, -OCOO-

-S-, -SO-, -so ₂ -,

-N-, -CO-N-, I I

^R 0 ^R 0 in these formulas, R _Q represents a hydrogen atom or an alkyl group having from 1 to 4 carbon atoms, a cyclohexyl or phenyl group.

More particularly, the optionally substituted residue A represents, the remainder:

a monocyclic, carbocyclic, aromatic compound, such as, for example, benzene, toluene, isobutylbenzene, anisole, thioanisole, phenetole or veratrole, guaiacol, guetol,

- a poiycyclic, condensed, aromatic compound, such as, for example, naphthalene, 2-methoxynaphthalene,

- a polycyclic, non-condensed, carbocyclic, aromatic compound, such as, for example, phenoxybenzene,

- a partially aromatic, condensed, carbocyclic, polycyclic compound, such as, for example, tetrahydronaphthalene, 1,2-methylene dioxybenzene,

- a polycyclic, non-condensed, carbocyclic, partially aromatic compound, such as, for example, cyclohexylbenzene,

a monocyclic, heterocyclic, aromatic compound, such as, for example, pyridine, furan, thiophene,

- a poiycyclic, condensed, aromatic, partially heterocyclic compound, such as, for example, quinoline, indole or benzofuran, - a polycyclic, non-condensed, aromatic, partially heterocyclic compound, such as, for example, phenylpyridines, naphthylpyridines,

- a polycyclic, condensed, partially aromatic, partially heterocyclic compound, such as, for example, tetrahydroquinoline, - a polycylic, non-condensed, partially aromatic, partially heterocyclic compound, such as, for example, cyclohexylpyridine.

In the process of the invention, use is preferably made of an aromatic compound of formula (I) in which A represents an aromatic ring, preferably a benzene or naphthalene ring. The aromatic compound of formula (I) can carry one or more substituents.

The number of substituents present on the cycle depends on the carbon condensation of the cycle and on the presence or not of unsaturations on the cycle. The maximum number of substituents likely to be carried by a cycle, is easily determined by a person skilled in the art.

In the present text, the term "several" is generally understood to mean less than 5 substituents on an aromatic ring.

Examples of substituents are given below, but this list is not limiting. We can cite in particular:

- linear or branched alkyl groups preferably having from 1 to 6 carbon atoms and even more preferably from 1 to 4 carbon atoms,

- linear or branched alkenyl groups preferably having from 2 to 6 carbon atoms and even more preferably from 2 to 4 carbon atoms, - linear or branched haloalkyl groups preferably having from 1 to 6 carbon atoms and from 1 to 13 halogen atoms and even more preferably from 1 to 4 carbon atoms and from 1 to 9 halogen atoms,

the cycloalkyl groups having from 3 to 6 carbon atoms, preferably the cyclohexyl group, the phenyl group,

- the benzyl group,

- the hydroxyl group,

- the NO2 group,

- The alkoxy groups R ^ -O- or thioether R1-S- in which R represents a linear or branched alkyl group having from 1 to 6 carbon atoms and even more preferably from 1 to 4 carbon atoms or the phenoxy group; alkenyloxy groups, preferably an allyloxy group, - -N- groups (R2> 2 in which the identical or different R2 groups represent a hydrogen atom, a linear or branched alkyl group having from 1 to 6 carbon atoms and even more preferably from 1 to 4 carbon atoms or a phenyl group, - -NH-CO-R2 groups in which the R2 group has the meaning given above,

- the carboxy groups or R2-O-CO- derivative in which the R2 group has the meaning given above,

- the acyloxy or aroyloxy groups R1-CO-O- in which the group R ^ has the meaning given above,

- a halogen atom, preferably a fluorine atom,

- a CF3 group.

- two R groups placed on two vicinal carbon atoms can form together and with the carbon atoms which carry them, a ring having 5 to 7 atoms, possibly including another heteroatom.

When n is greater than or equal to 2, two R groups and the two successive atoms of the aromatic ring can be linked together by an alkylene, alkenylene or alkenylidene group having from 2 to 4 carbon atoms to form a saturated, unsaturated or aromatic heterocycle having 5 to 7 carbon atoms. One or more carbon atoms can be replaced by another heteroatom, preferably oxygen or sulfur. Thus, the R groups can represent a methylenedioxy or ethylenedioxy group or a methylenedithio or ethylenedithio group.

The present invention applies very particularly to aromatic compounds corresponding to formula (I) in which the group or groups R represent an electron-donor group.

"Electro-donor group" means a group as defined by H.C.

BROWN in Jerry MARCH - Advanced Organic Chemistry, Chapter 9, pages 243 and 244 (1985). The aromatic compounds preferably used correspond to formula (la):

in which :

- A symbolizes the rest of a cycle forming all or part of a carbocyclic or heterocyclic, aromatic, monocyclic or poiycyclic system: said cyclic residue being able to carry a group R representing an atom of hydrogen or one or more identical or different electron-donor substituents,

- n represents the number of substituents on the cycle.

As examples of preferred electron donor groups R, there may be mentioned: a linear or branched alkyl group having from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl,

a linear or branched alkenyl group having from 2 to 6 carbon atoms, preferably from 2 to 4 carbon atoms, such as vinyl, allyl, a cyclohexyl, phenyl or benzyl group,

a linear or branched alkoxy group having from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms such as methoxy, ethoxy, propoxy, isopropoxy, butoxy groups, an alkenyloxy group, preferably an allyloxy group or a phenoxy group, a hydroxyl group,

a substituted amino group -N- (R2) 2 in which R2 has the meaning given above,

- Two R groups can be linked and form alkylenedioxy or alkylenedithio groups, preferably a methylenedioxy, ethylenedioxy, methylenedithio or ethylenedithio group.

In formula (la), n is a number less than or equal to 4, preferably equal to 1 or 2.

As mentioned previously, the process of the invention applies very particularly to effect the acylation of aromatic ethers and thioethers.

The preferred formulas of said compounds are the following:

Y R '

in which :

- Y represents an oxygen or sulfur atom, - A symbolizes the rest of a cycle forming all or part of an aromatic, monocyclic or polycyclic carbocyclic system, system comprising at least one group YR ': said cyclic residue being able to carry one or more substituents,

- R represents one or more substituents, identical or different, - R 'represents a hydrocarbon group having from 1 to 24 carbon atoms, which can be an acyclic saturated or unsaturated, linear or branched aliphatic group; a saturated, unsaturated or aromatic, monocyclic or polycyclic cycloaliphatic group; a saturated or unsaturated, linear or branched aliphatic group, carrying a cyclic substituent,

- R 'and R can form a cycle optionally comprising another heteroatom,

- n is a number less than or equal to 4.

In the present text, a simplified designation is made of "alkoxy or thioether groups", respectively groups of the R'-O- or R'-S- type in which R 'has the meaning given above. R 'therefore represents both an acyclic or cycloaliphatic, saturated, unsaturated or aromatic aliphatic group as well as a saturated or unsaturated aliphatic group carrying a cyclic substituent. The aromatic ether or thioether which is involved in the process of the invention corresponds to the formula (D in which R 'represents an acyclic aliphatic group, saturated or unsaturated, linear or branched.

More preferably, R ′ represents a linear or branched alkyl group having from 1 to 12 carbon atoms, preferably from 1 to 6 carbon atoms: the hydrocarbon chain can possibly be interrupted by a heteroatom (for example, oxygen), by a functional group (for example -CO-) and / or carrying substituents (for example, one or more halogen atoms).

The acyclic, saturated or unsaturated, linear or branched aliphatic group may optionally carry a cyclic substituent. The term “ring” is preferably understood to mean a saturated, unsaturated or aromatic carbocyclic ring, preferably cycloaliphatic or aromatic, in particular cycloaliphatic ring comprising 6 carbon atoms in the ring or benzene.

The acyclic aliphatic group can be linked to the cycle by a valential link, a heteroatom or a functional group and examples are given above.

The ring can be optionally substituted and, by way of examples of cyclic substituents, it is possible, among others, to consider substituents such as R, the meaning of which is specified for formula (I '). R 'can also represent a saturated carbocyclic group or comprising 1 or 2 unsaturations in the ring, generally having from 3 to 8 carbon atoms, preferably 6 carbon atoms in the ring; said cycle possibly being substituted by substituents such as R. R 'can also represent an aromatic carbocyclic group, preferably monocyclic generally having at least 4 carbon atoms, preferably 6 carbon atoms in the ring; said ring possibly being substituted by substituents such as R. In the general formula 0 ′) of aromatic ethers or thioethers, the remainder

A may represent the remainder of an aromatic, monocyclic carbocyclic compound having at least 4 carbon atoms and preferably 6 carbon atoms or the remainder of a polycyclic carbocyclic compound which may consist of at least 2 aromatic carbocycles and forming therebetween ortho- or ortho- and pericondensed systems or by at least 2 carbocycles of which at least one of them is aromatic and forming between them ortho- or ortho- and pericondensed systems. Mention may more particularly be made of a naphthalene residue.

The remainder A can carry one or more substituents on the aromatic ring.

Reference may be made to the examples of substituents given for formula (I), but this list is not limiting. Any substituent can be present on the cycle as long as it does not interfere with the desired product. The remainder A can, inter alia, carry several alkoxy groups, it is possible according to the process of the invention to acylate polyalkoxylated compounds.

In the formula (D, R more preferably represents one of the following atoms or groups:

an alkyl group, linear or branched, having from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl,

a linear or branched alkoxy group having from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms such as the methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy groups, - a halogen atom, preferably a fluorine, chlorine or bromine atom, a trifluoromethyl group.

The process of the invention applies more particularly to aromatic ethers or thioethers of formula (a):

in which : - n is a number less than or equal to 4, preferably equal to 0 or 1,

- Y represents an oxygen or sulfur atom,

the group R ′ represents an alkyl group, linear or branched, having from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl , tert-butyl or a phenyl group,

- the group or groups R, which are identical or different, represent one of the following atoms or groups:

. a hydrogen atom,. a linear or branched alkyl group preferably having from 1 to 6 carbon atoms and even more preferably from 1 to 4 carbon atoms,

. a linear or branched alkenyl group preferably having from 2 to 6 carbon atoms and even more preferably from 2 to 4 carbon atoms,. a linear or branched haloalkyl group preferably having from 1 to

6 carbon atoms and from 1 to 13 halogen atoms and even more preferably from 1 to 4 carbon atoms and from 1 to 9 halogen atoms,

. a cycloalkyl group having 3 to 6 carbon atoms, preferably a cyclohexyl group,

. a phenyl group,

. a benzyl group,

. a hydroxyl group,

. a NO2 group,. an alkoxy group R- | -0- or thioether R ^ -S- in which R 1 represents a linear or branched alkyl group having from 1 to 6 carbon atoms and even more preferably from 1 to 4 carbon atoms or a phenyl group; an alkenyloxy group, preferably an allyloxy group,

. a group -N- (R2) 2 in which the identical or different R2 groups represent a hydrogen atom, a linear or branched alkyl group having from 1 to 6 carbon atoms and even more preferably from 1 to

4 carbon atoms or a phenyl group,

. a group -NH-CO-R2 in which the group R2 has the meaning given above,. a carboxy group or derivative R ₂ -0-CO- in which the group R2 has the meaning given above,

. an acyloxy or aroyloxy group R ^ CO-O- in which the group R ^ has the meaning given above, . a halogen atom, preferably a fluorine atom,. a CF3 group.

- The groups R 'and R placed on two vicinal carbon atoms can form together and with the carbon atoms which carry them, a ring having 5 to 7 atoms, possibly including another heteroatom.

When n is greater than or equal to 1, the groups R ′ and R and the 2 successive atoms of the benzene ring can be linked together and form an alkylene, alkenylene or alkenylidene group having from 2 to 4 carbon atoms to form a saturated heterocycle , unsaturated or aromatic having 5 to 7 atoms. One or more carbon atoms can be replaced by another heteroatom, preferably oxygen or sulfur. Thus, the groups OR 'and R can represent a methylenedioxy or ethylenedioxy group and the groups SR' and R can represent a methylenedithio or ethylenedithio group.

In formula (a), R ′ preferably represents an alkyl group, linear or branched, having from 1 to 6 carbon atoms, preferably a methyl or ethyl group or a phenyl group.

The benzene nucleus carries one or more identical or different substituents R. R preferably represents an alkyl group, linear or branched, having from 1 to 6 carbon atoms, preferably a methyl or ethyl group; an alkoxy group, linear or branched, having from 1 to 4 carbon atoms, preferably a methoxy or ethoxy group.

The process of the invention applies more particularly to aromatic ethers or thioethers of formula f1) or (a) in which:

- n is equal to 0 or 1, - R 'represents an alkyl group, linear or branched, having from 1 to 6 carbon atoms or a phenyl group, preferably a methyl or ethyl group,

- R represents an alkyl group, linear or branched, having from 1 to 6 carbon atoms, preferably a methyl or ethyl group; an alkoxy group, linear or branched, having from 1 to 4 carbon atoms, preferably a methoxy or ethoxy group.

- The groups YR 'and R form a methylenedioxy, ethylenedioxy, methylenedithio or ethylenedithio group.

By way of illustration of compounds corresponding to formula (I) or (I '), there may be mentioned more particularly: - aromatic compounds such as benzene, toluene, fluorobenzene, chlorotoluenes, fluorotoluenes, trifluoromethoxybenzene, trichloromethoxybenzene , trifluoromethylthiobenzene,

- amino aromatic compounds such as aniline, - phenolic compounds such as phenol, o-cresol, guaiacol, guetol, I '-naphthol, β-naphthol,

- monoethers such as anisole, ethoxybenzene (phenetole), propoxybenzene, isopropoxybenzene, butoxybenzene, isobutoxybenzene, 1-methoxynaphthalene, 2-methoxynaphthalene, 2-ethoxynaphthalene; substituted monoethers such as 2-chloroan isolates, 3-chloroanisole, 2-bromoanisole, 3-bromoanisole, 2-methyian isolates, 3-methylanisole, 2-ethylanisole, 3-ethylanisole, 2- isopropylanisole, 3-isopropylanisole, 2-propylanisole, 3-propylanisole, 2-allylan isolate, 2-butylanisole, 3-butylanisole, 2-benzylanisole, 2-cyclohexylanisole, 1-bromo-2- ethoxybenzene, 1-bromo-3-ethoxybenzene, 1-chloro-2-ethoxybenzene, 1-chloro-3-ethoxybenzene, 1-ethoxy-2-ethylbenzene, 1-ethoxy-3-ethylbenzene, 1- 2-methoxy-allyloxybenzene, 2,3-dimethylanisole, 2,5-dimethylanisole, - diethers such as veratrole, 1, 3-dimethoxybenzene, 1, 4-dimethoxybenzene, 1, 2-diethoxybenzene, 1 , 3-diethoxybenzene, 1,2-dipropoxybenzene, 1, 3-dipropoxybenzene, 1, 2-methylenedioxybenzene, 1, 2-ethylenedioxybenzene,

- triethers such as 1,2,3-trimethoxybenzene, 1,3,5-trimethoxybenzene, 1,3,5-triethoxybenzene,

- thioethers such as thioanisole, o-thiocresol, m-thiocresol, p-thiocresol, 2-thioethylnaphthalene, S-phenylthioacetate, 3- (methylmercapto) aniline, phenylthiopropionate.

The compounds to which the process according to the invention applies more particularly advantageously are benzene, toluene, isobutylbenzene, anisole, phenetole, veratrole, 1,2-methylenedioxybenzene, 2-methoxynaphthalene and thioanisole.

As regards the acylation reagent, use is made of carboxylic acids and their derivatives, halides or anhydrides, preferably anhydrides.

The acylation reagent more particularly corresponds to formula (II):

in which :

- R3 represents:. a saturated or unsaturated, linear or branched aliphatic group having from 1 to

24 carbon atoms; a cycloaliphatic group, saturated, unsaturated or aromatic, monocyclic or polycyclic, having from 3 to 8 atoms carbon; a saturated or unsaturated, linear or branched aliphatic group, carrying a cyclic substituent,

- X 'represents:

. a halogen atom, preferably a chlorine or bromine atom,. a hydroxyl group,

. a group -0-CO-R ₄ with R ₄ , identical or different from R ₃ , having the same meaning as R3: R3 and R4 can together form a divalent aliphatic saturated or unsaturated group, linear or branched, having at least 2 atoms of carbon. By cyclic substituent, we refer to what is described above.

More preferably, R3 represents a linear or branched alkyl group having from 1 to 12 carbon atoms, preferably from 1 to 6 carbon atoms: the hydrocarbon chain can possibly be interrupted by a heteroatom (for example, oxygen), by a functional group (for example -CO-) and / or carrying a substituent (for example, a halogen or a group CF3).

R3 preferably represents an alkyl group having from 1 to 4 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl or a cycloalkyl group having from 3 to 8 carbon atoms, preferably a cyclopentyl or cyclohexyl group.

R3 also represents an alkenyl group having from 2 to 10 carbon atoms, such as in particular, vinyl, propen-yl, buten-yl, penten-yl, hexen-yl, octen-yl, decen-yl.

The group R ₃ also preferably represents a phenyl group which may be optionally substituted. Any substituent can be present on the cycle as long as it does not interfere with the desired product.

R3 also represents a phenylalkyl group having from 7 to 12 carbon atoms, preferably a benzyl group. As more specific examples of substituents, mention may be made, in particular:

an alkyl group, linear or branched, having from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, a linear or branched alkoxy group having from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms such as the methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy groups,

- a hydroxyl group, - a halogen atom, preferably a fluorine, chlorine or bromine atom.

The preferred acylating agents are acid anhydrides. They correspond more particularly to formula (II) in which R3 and R4 are identical and represent an alkyl group having from 1 to 4 carbon atoms or a phenyl group.

When the acylating agent is an acid halide, it preferably corresponds to formula (II) in which X 'represents a chlorine atom and R3 represents a methyl or ethyl or phenyl group.

By way of illustration of acylating agents corresponding to formula (II), there may be mentioned more particularly:

- acetic anhydride,

- propanoic anhydride,

- butyric anhydride,

- isobutyric anhydride, - trifluoroacetic anhydride,

- benzoic anhydride.

- monochloroacetyl anhydride,

- dichloroacetic anhydride,

- acetyl chloride, - monochloroacetyl chloride,

- dichloroacetic chloride,

- propanoyl chloride,

- isobutanoyl chloride,

- pivaloyl chloride, - stearoyl chloride,

- crotonyl chloride,

- benzoyl chloride,

- chlorobenzoyl chlorides,

- p-nitrobenzoyl chloride - methoxybenzoyl chlorides,

- naphthoyl chlorides,

- acetic acid,

- benzoic acid.

Acetic, propanoic, benzoic, monochloroacetyl, dichloroacetic anhydride, benzoyl chlorides, are the preferred acylating agents. In accordance with the process of the invention, the first step is the acylation of the aromatic compound of formula (I), preferably ((! '), (La) and even more preferably (a) using the compound of formula (II), in the presence of a catalyst.

A first variant of the process of the invention consists in carrying out the acylation of the aromatic compound of formula (I), in the presence of a zeolitic catalyst.

By "zeolite" is meant a crystallized tectosilicate of natural or synthetic origin whose crystals result from the three-dimensional assembly of tetrahedral units of Siθ4 and TO4: T representing a trivalent element such as aluminum, gallium, boron, iron, preferably aluminum. The aluminosilicate type zeolites are the most common.

Zeolites present within the crystal lattice, a system of cavities linked together by channels of a well-defined diameter called pores.

Zeolites can have a network of one-dimensional, two-dimensional or three-dimensional channels.

In the process of the invention, use may be made of a natural or synthetic zeolite.

As examples of natural zeolites which may be used, there may be mentioned, for example: chabazite, clinoptilolite, erionite, phillipsite, offerite.

Synthetic zeolites are entirely suitable for implementing the invention.

Examples of synthetic zeolites with a one-dimensional network include, among others, zeolite ZSM-4, zeolite L, zeolite ZSM-12, zeolite ZSM-22, zeolite ZSM-23, zeolite ZSM-48.

By way of examples of zeolites with a two-dimensional network preferably used, mention may be made of mordenite, ferrierite.

With regard to the zeolites with three-dimensional lattice, one can name more particularly, the zeolite β, the zeolite Y, the zeolite X, the zeolite ZSM-5, the zeolite ZSM-11, the offerite.

We preferentially use synthetic zeolites and more particularly zeolites which are in the following forms:

- the mazzite with an Si / Ai molar ratio of 3.4,

- the zeolite L with an Si / Ai molar ratio of 1.5 to 3.5, - the mordenite with an Si / Ai molar ratio of 5 to 100, preferably from 5 to

50,

- the ferrierite with a Si / Ai molar ratio of 3 to 10,

- the offer of Si / Ai molar ratio from 4 to 8.5. β zeolites with an Si / Ai molar ratio greater than 8, preferably between 10 and 100, and even more preferably between 12 and 50,

- Y zeolites, in particular the zeolites obtained after dealumination treatment (for example hydrotreatment, washing with hydrochloric acid or treatment with SiCLj) and mention may more particularly be made of US-Y zeolites with a Si / molar ratio Ai greater than 2, preferably between 4 and 60;

the zeolite X of the faujasite type with an Si / Ai molar ratio of 0.7 to 1.5,

- ZSM-5 zeolites or aluminum silicalite with Si / Ai molar ratio from 10 to 500,

- ZSM-11 zeolite with an Si / Ai molar ratio of 5 to 30.

- the mesoporous zeolite of MCM type, more particularly MCM-22 and MCM-41 with an Si / Al molar ratio of between 10 and 100, preferably between 15 and 40. The zeolites are advantageously used in acid form.

Among all these zeolites, use is preferably made in the process of the invention of the mordenite, β or Y zeolites in acid form.

The zeolites used in the process of the invention are known products described in the literature [cf. Atlas of zeolites structure types by W. M. Meier and D. H. Oison published by the Structure Commission of the International Zeolite Association (1978)].

One can use commercially available zeolites or else synthesize them according to the methods described in the literature.

We can refer to the aforementioned Atlas, and more particularly, for the preparation:

- from zeolite L to the publication by Barrer R. M. et al, Z. Kristallogr., 128. pp. 352 (1969)

- From the zeolite ZSM-12, to US patent 3,832,449 and to the article LaPierre et al, Zeolites 5, pp. 346 (1985), - from the zeolite ZSM-22, to the publication Kokotailo G.T. et al, Zeolites 5, pp. 349 (1985),

- From the zeolite ZSM-23, to US Pat. No. 4,076,842 and to the article Rohrman A. C. et al, Zeolites 5, pp. 352 (1985),

- from the zeolite ZSM-48, to the work of Schlenker J. L. et al, Zeolites 5, pp. 355 (1985),

- β zeolite, to US patent 3,308,069 and to the article Caullet P. et al, Zeolites 12, pp. 240 (1992),

- from mordenite, to the works of Itabashi et al, Zeolites £, pp. 30 (1986), - from zeolites X and Y respectively to patents US 2,882,244 and US 3,130,007,

- from the zeolite ZSM-5, to US patent 3,702,886 and to the article Shiralkar VP et al, Zeolites â, PP- 363 (1989), - from the zeolite ZSM-11, to the work of Harrison ID et al, Zeolites L PP-

21 (1987),

- the mesoporous zeolite of MCM type, in the article by Beck et al, J. Am. Chem. Soc. JJ4 (27), pp. 10834-43 (1992).

The zeolite constitutes the catalytic phase. It can be used alone or mixed with a mineral matrix. In the description, the term “catalyst” will denote the catalyst produced entirely from a zeolite or from a mixture with a matrix prepared according to techniques known to those skilled in the art.

To this end, the matrix can be chosen from metal oxides, such as aluminum, silicon and / or zirconium oxides, or also from clays and more particularly, kaolin, talc or montmorillonite.

In the catalyst, the active phase content represents from 5 to 100% of the weight of the catalyst.

The catalysts can be in different forms in the process of the invention: powder, shaped products such as granules (for example, extruded or balls), pellets, which are obtained by extrusion, molding, compacting or any other type of known process. In practice, on the industrial level, it is the forms of granules or beads which have the most advantages both in terms of efficiency and in terms of ease of use. According to the invention, the acylation reaction is advantageously carried out in the liquid phase comprising the aromatic compound and the acylating agent, in the presence of the catalyst.

One of the starting reagents can serve as reaction solvent but it is also possible to use an organic solvent. An organic solvent is chosen, which is less activated than the starting substrate and which preferably dissolves it.

As examples of solvents suitable for the present invention, there may be mentioned in particular aliphatic or aromatic hydrocarbons, halogenated or not, aliphatic, cycloaliphatic or aromatic ether-oxides. As examples of aliphatic hydrocarbons, there may be mentioned more particularly paraffins such as in particular, hexane and cyclohexane, aromatic hydrocarbons and more particularly aromatic hydrocarbons such as in particular benzene, toluene, xylenes, cumene , petroleum fractions consisting of a mixture of alkylbenzenes, in particular the Solvesso® type fractions.

With regard to aliphatic or aromatic halogenated hydrocarbons, there may be mentioned more particularly, perchlorinated hydrocarbons such as in particular tetrachlorethylene, hexachloroethane; partially chlorinated hydrocarbons such as 1, 2-dichloroethane, dichlorobenzene.

It is also possible to use, as organic solvents, the aliphatic, cycloaliphatic or aromatic ether-oxides and, more particularly, dipropyl ether, diisopropyl ether, dibutyl ether, methyl tert-butyl ether, dimethyl ether of ethylene glycol (or glyme), dimethyl ether of diethylene glycol (or diglyme); phenyl oxide; dioxane, tetrahydrofuran (THF).

As examples of aprotic, more polar organic solvents which can also be used in the process of the invention, there may be mentioned more particularly nitro compounds such as, for example, nitromethane, nitroethane, 1-nitropropane, 2- nitropropane or their mixtures, nitrobenzene; alphatic or aromatic nitriies such as acetonitrile, itri propion, benzonitrile, benzyl cyanide; linear or cyclic carboxamides such as N, N-dimethylacetamide (DMAC), N, N-diethylacetamide, dimethylformamide (DMF), diethylformamide or 1-methyl-2-pyrrolidinone (NMP); dimethylsu If oxide (DMSO); tetramethylenesulfone (sulfolane); hexamethylphosphotriamide (HMPT).

The preferred solvents are: dichloroethane, dichlorobenzene, dimethyl ether of ethylene glycol (or glyme), dimethyl ether of diethylene glycol (or diglyme), dioxane.

It is also possible to use a mixture of organic solvents. Preferably, the starting substrate is used as the reaction solvent. As mentioned previously, the aromatic compound is reacted with an acylating agent, optionally in the presence of a reaction solvent as defined and in the presence of a zeolitic catalyst.

The ratio between the number of moles of aromatic compound and the number of moles of acylating agent can vary because the substrate can serve as a reaction solvent. Thus, the ratio can range from 0.1 to 10, and is preferably between 0.5 and 4.0.

The amount of catalyst which is used in the process of the invention can vary within wide limits. When the process is carried out batchwise, the catalyst may represent, by weight relative to the aromatic compound used, from 0.01 to 50%, preferably from 5 to 25%. However, if the process is carried out continuously, for example by reacting a mixture of the aromatic compound and the acylating agent on a fixed bed of catalyst, these catalyst / aromatic compound ratios are meaningless and at a given time, there may be an excess weight of catalyst relative to the starting aromatic compound.

As regards the quantity of organic solvent used, it is generally chosen so that the ratio between the number of moles of organic solvent and the number of moles of aromatic compound preferably varies between 0 and 100 and even more preferably between 0 and 50.

The temperature at which the acylation reaction is carried out depends on the reactivity of the starting substrate and that of the acylating agent. It is between 20 ° C and 300 ° C, preferably between 40 ° C and 150 ° C.

Generally, the reaction is carried out at atmospheric pressure but lower or higher pressures may also be suitable. One works under autogenous pressure when the reaction temperature is higher than the boiling point of the reactants and / or of the products. From a practical point of view, the process can be carried out batchwise or continuously.

According to the first variant, there are no constraints with regard to the use of the reagents. They can be entered in any order. After bringing the reactants into contact, the reaction mixture is brought to the desired temperature.

The other variant of the invention consists in carrying out the reaction continuously, in a tubular reactor comprising the solid catalyst placed in a fixed bed.

The aromatic compound and the acylating agent can be introduced separately or as a mixture into the reactor. Said mixture is passed over a catalytic bed comprising at least one zeolite and then the reaction mixture from the catalytic bed is subjected to recirculation on a catalytic bed, in a number of times sufficient to obtain the desired substrate conversion rate.

The acylation of an aromatic compound on a zeolite catalytic bed with recirculation of the reaction mixture is a technique described in PCT / FR 97/01066 published under the number WO 97/48665 which is incorporated by reference in the present application. The reaction mixture passes through the catalytic bed, preferably from bottom to top and at its outlet is returned to the reagent mixing zone in order to be recycled a number of times sufficient to obtain the desired conversion rate of the substrate, preferably, greater than 20%, and even more preferably between 50 and 100%. The substrate conversion rate is defined as the ratio between the number of moles of substrate transformed over the number of moles of substrate introduced.

The linear speed of the liquid flow on the catalytic bed advantageously varies between 0.1 and 10 cm / s, preferably between 0.1 and 5 cm / s. The residence time of the material flow on the catalytic bed varies, for example, between 15 min and 10 h, and preferably between 30 min and 5 h.

At the end of the reaction, a liquid phase is recovered comprising the aromatic ketone compound which can be recovered in a conventional manner, by distillation or by recrystallization from an appropriate solvent, for example water or alcohols (methanol, ethanol), after preliminary elimination. excess reagents.

The product obtained the following formula (III):

- in which R, R3, A and n have the meaning given above. The process of the invention gives preferential access to the compound of formula (IN '):

Y R '

- in which R, R ', R3, Y, A and n have the meaning given above.

The compounds of the formula (IIIa):

- in which R, R ', R3, Y and n have the meaning given above.

Another variant of the invention consists in making use of a homogeneous catalysis by using Friedel-Crafts catalysts of organic or mineral type. As examples of salts comprising an organic counterion, mention may in particular be made of acetate, propionate, benzoate, methanesulfonate, trifluoromethanesulfonate of metallic or metalloid elements of groups (IIIa), (IVa), (VIII), ( llb), (lllb), (IVb), (Vb) and (Vlb) of the Periodic Table of the Elements.

As regards the salts comprising an inorganic counterion, mention may be made of chlorides, bromides, iodides, sulfates, phosphates, nitrates, oxides and similar products of the metallic or metalloid elements of the groups

(lia), (llla), (IVa), (VIII), (llb), (lllb), (IVb), (Vb) and (Vlb) of the periodic table.

In this text, reference is made below to the Periodic Table of Elements published in the Bulletin de la Société Chimique de France, No. 1 (1966).

The salts used in the process of the invention are more particularly those of the elements of group (IIa) of the periodic classification preferably, magnesium; of the group (IIIa) preferably, scandium, yttrium and the lanthanides; preferably group (IVa), titanium, zirconium; preferably group (VIII), iron; preferably group (llb), zinc; preferably group (IIIb), boron, aluminum, gallium, indium; preferably group (IVb), tin; of the group (Vb) preferably, bismuth; of the group (Vlb) preferably tellurium.

Among the inorganic salts, mention may be made of metal halides and preferably magnesium chloride, zirconium chloride, ferric chloride, zinc chloride, aluminum chloride, aluminum bromide, gallium chloride, indium chloride, stannic chloride, bismuth chloride, boron trifluoride.

As regards the organic salts, use is preferably made of the rare earth and / or bismuth salts of trifluoromethanesulfonic acid commonly known as "triflic acid". By "rare earth" is meant the lanthanides having an atomic number of

57 to 71 and ryttrium as well as scandium.

In the process of the invention, the following rare earths are more particularly envisaged: lanthanum, ytterbium, lutetium and / or scandium.

Rare earth triflates are known products which are described in the literature, in particular in US-A-3,615,169. They are generally obtained by reaction of rare earth oxide and trifluoromethanesulfonic acid. The bismuth salts of triflic acid described in patent application PCT / FR96 / 01488 can also be used in the process of the invention.

In accordance with the process of the invention, the acylation reaction of the compound of formula (I) is carried out.

The process of the invention can be carried out in an organic solvent, for example isopropyl ether, but one of the reagents can also be used as reaction solvent.

It is desirable that the solvent is anhydrous. The ratio between the number of moles of the compound of formula (I) and the number of moles of acylating agent [compound of formula (II)] can vary because the substrate can serve as reaction solvent. Thus, the ratio can range from 1 to 10, preferably from 1 to 4.0.

The amount of catalyst used is determined so that the ratio between the number of moles of catalyst and the number of moles of compound of formula (II) is preferably between 0.001 and 2.0, and even more preferably between 0.05 and 1.0.

The temperature at which the acylation reaction is carried out depends on the reactivity of the starting substrate and that of the acylating agent. It is between 20 ° C and 200 ° C, preferably between 40 ° C and 120 ° C.

Generally, the reaction is carried out at atmospheric pressure but lower or higher pressures may also be suitable.

It is preferred to carry out the reaction under a controlled atmosphere of inert gases such as nitrogen or rare gases, for example argon. From a practical point of view, the compound of formula (I) is preferably used, the catalyst then the compound of formula (II).

After bringing the reactants into contact, the reaction mixture is brought to the desired temperature.

The duration of the reaction is a function of many parameters. Most often, it is from 1 hour to 8 hours.

After the acylation step of the compound of formula (I), the aromatic ketone compound which corresponds to formula (III) is preferably obtained (III ′) and even more preferably (IIIa).

It is recovered in a conventional manner, from the reaction medium. For this purpose, most often one begins by carrying out a deactivation treatment of the catalyst, either by extraction with water or either by adding a solution of a basic agent, preferably ammonia or carbonate or sodium hydrogencarbonate, then separation of the aqueous and organic phases.

It is then recovered from the organic phase, according to known techniques, in particular by distillation or by recrystallization from an appropriate solvent optionally in the presence of water, preferably an alcohol, for example methanol, isopropanol or butanol. ; a ketone, for example methyl ethyl ketone or methyl isobutyl ketone.

The acylation step is preferably carried out in the presence of a catalyst of the zeolitic type.

In accordance with the process of the invention, in the second step, the hydrogenation of the carbonyl group to the carbinol group is carried out.

OH

A first variant of the process of the invention consists in carrying out a hydrogenation in the presence of conventional hydrogenation catalysts.

As preferred catalysts, metals from group VIII of the periodic table are used, preferably noble metals, cobalt or nickel.

Thus, it is possible to use a finely divided noble metal, from group VIII of the periodic table of elements such as platinum, palladium, rhodium, iridium, ruthenium or osmium.

Said metal can be provided in a finely divided form or else deposited on a support. As examples of supports, mention may be made of carbon, acetylene black, silica, alumina, zirconia, chromium oxide, bentonite, etc.

The metal can be deposited on the support in metallic form or else in the form of a compound which will be reduced to metal in the presence of hydrogen. Among other things, it is possible to use an oxide of one of the aforementioned noble metals.

The preferred metals are platinum and palladium, preferably deposited on carbon black.

Preferably, the platinum and / or palladium is deposited on a support. Generally, it is deposited at a rate of 0.5% to 5% of the weight of the catalyst. The amount of hydrogenation catalyst used, expressed by weight of catalyst per weight of keto aromatic compound can vary, for example, between 0.5 and 20%, preferably between 1 and 5%.

Other hydrogenation catalysts which are quite suitable for the process of the invention are Raney nickel and Raney cobalt.

Commercial forms of Raney nickel are used, which can contain the conventional impurities found in this type of catalyst, namely chromium and / or iron, without disadvantage.

In this case, the amount of hydrogenation catalyst used, expressed by weight of catalyst per weight of ketone aromatic compound can vary, for example, between 1 and 10%, preferably between 3 and 6%.

The catalyst can be used in the form of a powder, pellets or else granules.

The amount of hydrogenation catalyst used, expressed by weight of catalyst per mole of ketone aromatic compound can vary, for example, between 0.5 and 20%, preferably between 1 and 5%.

The process of the invention is carried out at a temperature chosen from a temperature range from 50 ° C to 120 ° C and chosen more particularly between 60 ° C and 100 ° C. The reaction takes place under hydrogen pressure ranging from a pressure slightly higher than atmospheric pressure to a pressure of several tens of bars. Advantageously, the hydrogen pressure varies between 1 and 50 bars, and more preferably between 3 and 10 bars.

The reaction is continued until the consumption of hydrogen ceases.

The process according to the invention is carried out in the liquid phase. A first variant of the process of the invention consists in carrying out the hydrogenation of the ketone compound, in bulk when the latter and the final product are in liquid form. Another variant of the process of the invention consists in carrying out the reaction in an organic solvent.

An organic solvent is chosen, which is less activated than the starting substrate and which preferably dissolves it.

An inert solvent can be used under the conditions of the reaction of the invention. Thus, it is possible to use saturated aliphatic or cycloaliphatic hydrocarbons such as hexane or cyclohexane, or aromatic hydrocarbons such as benzene, toluene, xylenes; alcohols such as methanol, ethanol, propanol, cyclohexanol; esters such as ethyl acetate, butyl acetate; polyol esters or ethers such as tetraethylene glycol diacetate; ethers such as dimethyl ether of ethylene glycol (or glyme), or dimethyl ether of diethylene glycol (or diglyme). The preferred solvents are methanol and ethanol. The concentration of the ketone compound of formula (III) or (III ') or (IIIa), used in the solvent can vary within very wide limits, until saturation under the operating conditions. Generally, it is not economically advantageous to use less than 5% by weight of ketone compound per volume of solvent. Generally, the concentration by weight of ketone compound per volume of solvent is between 20% and 75% and preferably between 40% and 60%.

In practice, the process according to the invention can be implemented by introducing into a inert autoclave the ketone compound of formula (III) or (IID or (IIIa), the catalyst, and the solvent, then, after the usual purges, by supplying the autoclave with an adequate pressure of hydrogen; the contents of the autoclave are then brought under stirring to the appropriate temperature until absorption ceases.The pressure in the autoclave can be kept constant during the duration of the reaction thanks to a reserve of gaseous mixture, which feeds it at the selected pressure.

At the end of the reaction, the autoclave is cooled and degassed. The reaction mixture is recovered and the catalyst separated according to conventional solid / liquid separation techniques.

A benzyl type alcohol is obtained, that is to say a compound comprising at least one aromatic heterocycle or carbocycle in which a hydrogen atom directly linked to the aromatic nucleus is replaced by a

I group - C - OH

The process of the invention leads to benzyl type alcohols

- in which R, R3, A and n have the meaning given above.

The process of the invention gives preferential access to the compound of formula (IV):

- in which R, R ', R, Y, A and n have the meaning given above.

The preferred compounds of the invention more particularly correspond to formula (IVa):

- in which R, R3 and n have the meaning given above.

The reaction medium can be used directly in the following stage, the reaction medium freed from the catalyst and comprising the benzyl alcohol in the etherification stage if the latter is carried out using methanol or ethanol. In the other cases, the benzyl alcohol obtained is separated according to conventional separation methods, for example distillation or crystallization, before engaging it in the etherification step.

When the benzyl alcohol obtained corresponding to formulas (IV), (IV) or (IVa) is a chiral alcohol, another variant of the process of the invention consists in carrying out an enantioselective hydrogenation of the ketone compound, in the presence of a complex preferably metallic based on rhodium, iridium, ruthenium or palladium and comprising an optically active diphosphine type ligand.

Thus, the diphosphine can be BINAP or else BIPNOR (bis- (1-phospha-2,3-diphenyl-4,5-dimethylnorbomadiene)).

The hydrogenation of the carbonyl group to the carbinol group in the presence of a metal complex comprising an optically active diphosphine as mentioned above can be carried out according to the teaching of PCT / FR97 / 01154 published under the number WO 98/00375 which is incorporated by reference in the this request.

In accordance with the process of the invention, the etherification of the hydroxyl group, which consists in reacting the benzyl alcohol with another alcohol, in the presence of an effective amount of a zeolite, is carried out in the third step. .

The benzyl alcohol obtained more particularly corresponds to formulas (IV) and even more preferably to formulas (IV) and (IVa). For convenience of language, the other alcohol used will be called generically by "alkanol" although it also denotes alcohols comprising in particular aromatic rings.

The benzyl type alcohols preferably used in the process of the invention are:

- vanillic alcohol,

- p-hydroxybenzyl alcohol,

- 1- (4-hydroxy-3-methoxyphenyl) ethanol,

- 2-hydroxybenzyl alcohol, - p-methoxybenzyl alcohol,

- 3,4-dimethoxybenzyl alcohol,

- 6-n-propyl-3,4-dimethoxybenzyl alcohol,

- alcohol (3,4-dimethoxyphenyl) dimethylcarbinol,

- alcohol 1 (3,4-dimethoxyphenyl) ethanol, - 1 - [1-hydroxy-2-methylpropyl] -3,4-dimethoxybenzene,

- 1- [1-hydroxy-2-methylpropyl] -3,4-diethoxybenzene,

- 1- [1-hydroxyethyl] -3,4-diethoxybenzene,

- 1- [1-hydroxyethyl] -3,4-dimethoxy-6-propylbenzene,

- 5- [1-hydroxyethyl] -1,3-benzodioxol, - naphthalene-2-methylol.

As regards the alkanol, it more particularly corresponds to the general formula (V):

R ₅ - OH (V) in said formula (V): - R5 represents a hydrocarbon group having from 1 to 24 carbon atoms, which can be a saturated or unsaturated, linear or branched acyclic aliphatic group; a saturated, unsaturated or aromatic cycloaliphatic group, a saturated or unsaturated, linear or branched aliphatic group, carrying a cyclic substituent. The alkanol which is involved in the process of the invention corresponds to the formula

(V) in which R5 represents an acyclic aliphatic group, saturated or unsaturated, linear or branched.

More specifically, R5 represents an alkyl, alkenyl, alkadienyl, alkynyl, linear or branched group preferably having from 1 to 24 carbon atoms. The hydrocarbon chain can optionally be:

- interrupted by one of the following groups: -O-, -CO-, -COO-, -OCOO-, -S-, -SO _? -, -N-, -CO-N-,

II in these formulas Rg represents hydrogen or a linear or branched alkyl group having from 1 to 4 carbon atoms, preferably a methyl or ethyl group,

- and / or carrier of one of the following substituents:

-OH, -OCOO-, -COOR ₆ , -CHO, -N0 ₂ , -X, -CFg in these formulas, Rβ having the meaning given above.

The acyclic, saturated or unsaturated, linear or branched aliphatic residue may optionally carry a cyclic substituent. By cycle is meant a carbocyclic or heterocyclic, saturated, unsaturated or aromatic cycle.

The aliphatic acyclic residue can be linked to the cycle by a valential bond or by one of the following groups:

-O-, -CO-, -COO-, -OCOO-, -S-, -SO _? -, -N-, -CO-N-,

II in these formulas, Rg having the meaning given previously.

As examples of cyclic substituents, it is possible to envisage cycloaliphatic, aromatic or heterocyclic, in particular cycloaliphatic substituents comprising 6 carbon atoms in the ring or benzenic, these cyclic substituents themselves being optionally carriers of 1, 2, 3, 4 or 5 groups R ", identical or different, R" having the meaning given above for the group R carried by the cycle of formula (I).

In the general formula (V) of the alkanols, R5 can also represent a carbocyclic group saturated or comprising 1 or 2 unsaturations in the ring, generally having from 3 to 7 carbon atoms, preferably 6 carbon atoms in the ring; said cycle being able to be substituted by 1 to 5 groups R "preferably 1 to 3, R" having the meanings stated previously for R.

As preferred examples of R5 groups, mention may be made of cyclohexyl or cyclohexene-yl groups, optionally substituted by linear or branched alkyl groups, having from 1 to 4 carbon atoms.

The process is easily carried out with most alkanols. As examples of alkanols, there may be mentioned:

- lower aliphatic alkanols having from 1 to 5 carbon atoms, such as for example, methanol, ethanol, trifluoroethanol, propanol, isopropyl alcohol, butanol, isobutyl alcohol, dry alcohol - butyl, tert-alcohol butyl, pentanol, isopentyl alcohol, dry pentyl alcohol and tert-pentyl alcohol, ethylene glycol monoethyl ether, methyl lactate, isobutyl lactate, methyl D-lactate, isobutyl D-lactate, propargyl alcohol, 3-chlorobut-2-en-1-ol, 2-butyn-1-ol, - higher aliphatic alcohols having at least 6 and up to about 20 carbon atoms, such as, for example, hexanol, Pheptanol, isoheptyl alcohol, octanol, isooctyl alcohol, 2-ethylhexanol, sec-octyl alcohol, tert-octyl alcohol, nonanol , isononyl alcohol, decanol, dodecanol, tetradecanol, octadecanol, hexadecanol, oleic alcohol, eicosyl alcohol, diethylene glycol monoethyl ether.

- cycloaliphatic alcohols having from 3 to approximately 20 carbon atoms, such as, for example, cyclopropanol, cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, cyclooctanol, cyclododecanol, tripropylcyclohexanol, methylcyclohexanol cyclopentèn-ol, cyclohexèn-ol,

- An aliphatic alcohol carrying an aromatic group having from 7 to about 20 carbon atoms such as for example benzyl alcohol, phenethyl alcohol, phenylpropyl alcohol, phenyloctadecyl alcohol and naphthyldecyl alcohol. It is also possible to use polyols, in particular polyoxyethylene glycols such as, for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, glycerol.

Among the abovementioned alcohols, the aliphatic or cycloaliphatic alcohols are preferably used in the process of the invention, preferably the primary or secondary aliphatic alcohols having 1 to 4 carbon atoms and cyclohexanol.

A preferred variant of the process of the invention consists in using a terpene alcohol and more particularly a terpene alcohol of formula (Va): T - OH (Va) in said formula (Va):

- T represents the remainder of a terpene alcohol having a number of carbon atoms multiple of 5.

In the following description of the present invention, the term "terpene" means oligomers derived from isoprene.

More precisely, the alcohol used corresponds to the general formula (Va) in which the residue T represents a hydrocarbon group having from 5 to 40 carbon atoms and more particularly an aliphatic group, saturated or unsaturated, linear or branched; a cycloaliphatic, saturated, unsaturated or aromatic, monocyclic or polycyclic group, comprising rings having from 3 to 8 carbon atoms.

It will be specified, without however limiting the scope of the invention, that the remainder T represents, the remainder:

- an aliphatic, saturated or unsaturated, linear or branched terpene alcohol,

- a cycloaliphatic, monocyclic, saturated or unsaturated, or aromatic terpene alcohol,

- a cycloaliphatic, poiycyclic terpene alcohol comprising at least two saturated and / or unsaturated carbocycles.

As regards the remainder T of an aliphatic, saturated or unsaturated, linear or branched terpene alcohol, the number of carbon atoms varies between 5 and 40 carbon atoms. As more specific examples of residue T, mention may be made of groups comprising 8 carbon atoms, saturated or having a double bond, and carrying two methyl groups, preferably in positions 3 and 7.

When it is a monocyclic compound, the number of carbon atoms in the ring can vary widely from 3 to 8 carbon atoms but it is preferably 5 or 6 carbon atoms and is most often carried by an aliphatic chain.

The carbocycle can be saturated or comprising 1 or 2 unsaturations in the cycle, preferably from 1 to 2 double bonds which are most often in the α position of the oxygen atom.

In the case of an aromatic terpene alcohol, the aromatic cycle is generally a benzene nucleus.

The compound can also be polycyclic, preferably bicyclic which means that at least two rings have two carbon atoms in common. In the case of polycyclic compounds, the number of carbon atoms in each cycle varies between 3 and 6: the total number of carbon atoms being preferably equal to 7.

Examples of the commonly encountered bicyclic structure are given below:

[4,1,0] [2,2,1] [3,1,1] [3,2,0]

In the case of a cycle, the presence of substituents is not excluded insofar as they are compatible with the intended application. Substitutes most often carried by the carbocycle are one or more alkyl groups, preferably three methyl groups, a methylene group (corresponding to an exocyclic bond), an alkenyl group, preferably an isopropene-yl group. As examples of terpene alcohols which may be used, there may be mentioned:

- saturated or unsaturated aliphatic terpene alcohols such as:

. 3,7-dimethyloctanol,

. tetrahydro-allocimenol,. hydroxycitronellol,

. 1-hydroxy 3,7-dimethyl 7-octene,

. nerol,

. geraniol,

. the linalool,. citronellol,

. 3,7-dimethyloct-6-en-1-ol

. 1-hydroxy 2-ethyl 5-isopropyl 8-methyl 2,7-nonadiene,

. 1-hydroxy 3,7,11-trimethyl 6,10-dodecadiene,

- aromatic cycloaliphatic terpene alcohols such as:. thymol,

- saturated or unsaturated, monocyclic or polycyclic cycloaliphatic terpene alcohols such as:

. chrysanthemum alcohol,

. 1-hydroxyethyl 2,2,3-trimethylcyclopentane,. terpinol hydrate,

. 1, 8-terpine,

. dihydro-terpineol,

. β-terpineol,

. perillyl alcohol,. 1-methyl 3-hydroxy 4-isopropylcyclohexene,

. α-terpineol,

. terpinene-4-ol,

. 1, 3,5-trimethyl 4-hydroxymethylcyclohexene,

. the carveol,. cis-2-pinanol,

. cis-3-pinanol,

. isoborneol,

. verbenol, . trans-pinocarveol,. campholenic alcohol,

. (2,3-dimethyl-tricyclo- [2.2.1.0 (2,6)] - heptyl-3) -5-methyl-2-pentene-2-ol-1 or santalol. Among all the abovementioned alcohols, the preferred alcohols are the following:

. chrysantemic alcohol,. 3,7-dimethyloctanol,. geraniol,. the linalool,. citronellol,

. hydoxycitronellol,. nerol,. thymol,. menthol,. isobomeol,

. verbenol.

In accordance with the process of the invention, the etherification reaction is carried out in the presence of a catalyst consisting of a zeolite.

We can use a natural or synthetic zeolite and we can refer to the previous description.

In this step, the preferred zeolites are the mordenite, β or Y zeolites in acid form.

The reaction of the benzyl alcohol of formula (IV) with the alkanol of formula (V) can be carried out in the presence or in the absence of an organic solvent, one of the reagents being able to be used as reaction solvent.

Preferably, the alkanol is used as the reaction solvent although other organic solvents can be used.

As examples of solvents suitable for the present invention, there may be mentioned, without limitation, aliphatic, cycloaliphatic or aromatic ether-oxides and, more particularly, dipropyl ether, diisopropyl ether, dibutyl ether, methyltertiobutylether, ethylene glycol dimethyl ether (or glyme), diethylene glycol dimethyl ether (or diglyme); phenyl oxide; dioxane, tetrahydrofuran (THF).

When the process is carried out batchwise, the catalyst can represent, by weight relative to the faulty reagent, from 2 to 50%, preferably from 5 to 20%. However, if the process is carried out continuously, for example by reacting a mixture of benzyl alcohol and alkanol on a fixed bed of catalyst, these catalyst / benzyl alcohol ratios have no effect. sense and at a given time, one can have an excess weight of catalyst compared to the starting benzyl alcohol.

The amount of alkanol of formula (V) expressed in moles of alkanol per mole of benzyl alcohol of formula (IV) can also vary within wide limits. The alkanol molar ratio of formula (V) / benzyl alcohol of formula (IV) can vary between 1 and 30. The upper limit is not critical, but however for economic reasons, there is no point in exceeding it.

The temperature of the etherification reaction can vary widely. It is chosen, advantageously between 50 ° C and 200 ° C and even more preferably between 50 ° C and 100 ° C.

Generally, the reaction is carried out at atmospheric pressure, but higher pressures may also be suitable, ranging from 1 to 50 bar, preferably from 1 to 25 bar. One works under autogenous pressure when the reaction temperature is higher than the boiling point of the reactants and / or of the products.

It is preferred to carry out the reaction under a controlled atmosphere of inert gases such as nitrogen or rare gases, for example argon.

The duration of the reaction can be very variable. It is most often between 15 minutes and 10 hours, preferably between 30 minutes and 5 hours.

From a practical point of view, the process can be carried out batchwise or continuously.

According to the first variant, it is possible to charge the catalyst, preferably the alkanol, of formula (V), optionally an organic solvent, then the benzyl alcohol, preferably of formula (IV), is introduced. A preferred embodiment of the invention consists in gradually introducing the benzyl alcohol, continuously or in fractions, then the reaction mixture is brought to the desired temperature. The other variant of the invention consists in carrying out the reaction continuously, in a tubular reactor comprising the solid catalyst placed in a fixed bed. The benzyl alcohol and the alkanol are preferably introduced separately. They can also be introduced into a solvent as mentioned above. The residence time of the material flow on the catalytic bed varies, for example, between 15 min and 10 hours, and preferably between 30 min and 5 hours. At the end of the reaction, a liquid phase is recovered comprising the etherified benzyl alcohol which can be recovered in a conventional manner. The process of the invention leads to etherified benzyl alcohols of preferred type I):

- in which R, R ₃ , R ₅ , A and n have the meaning given above.

The process of the invention gives preferential access to the compound of formula (VI '):

- in which R, R ', R3, R5, Y, A and n have the meaning given above. The preferred compounds of the invention more particularly correspond to the formula (Via):

- in which R, R ₃ , R ₅ and n have the meaning given above.

The process of the invention is particularly well suited for the preparation of mixed ethers, that is to say ethers in which the group R5 is different from the group of benzyl type.

Examples of the invention are given below. These examples are given by way of illustration and without limitation. In the examples, the conversion rate and the yield obtained are defined.

The conversion rate (TT) corresponds to the ratio between the number of substrates transformed and the number of moles of substrate engaged.

The yield (RR) corresponds to the ratio between the number of moles of product formed and the number of moles of substrate used. EXAMPLES

Step 1 Acetylation of the veratrole:

Example 1

100 g of acetoveratrole and 73.8 g of acetic anhydride are introduced into a 500 ml glass reactor.

Stirred and 10 g of a catalyst comprising 60% of binder (silica) and 40% of a SPRAY DRIED H-Y zeolite (Si / Al ratio of 15) are added.

It is heated to 90 ° C. and the temperature is maintained for 3 hours under these conditions.

The temperature is then brought back to 50 ° C. and filtered on sintered glass.

By analysis by vapor phase chromatography, a conversion rate of veratrole (TT) of 44% and a yield of acetoveratrole (RR) of 43% are determined.

Example 2

The above example is reproduced but using an unsupported zeolite powder, ie 4 g of Zeolyst H-Y 720 zeolite (Si / Ai ratio of

15).

By analysis by vapor phase chromatography, a conversion rate of veratrole (TT) of 58% is determined and a yield of acetoveratrole

(RR) of 55%.

Example 3

The preceding example is reproduced, but using an unsupported powder zeolite, ie 4 g of Zeolyst H-β CP 811 zeolite (Si / Ai ratio of 12.5). By analysis by vapor phase chromatography, a conversion rate of veratrole (TT) of 36% is determined and a yield of acetoveratrole

(RR) of 30%.

EXAMPLE 4 40 g of a zeolitic catalyst in the form of extrudates containing 20% of alumina and 80% of a HY 712 zeolite (Si / Ai ratio of 5.0) are charged to a 100 ml glass reactor. .

400 g of veratrole and 147.6 g of acetic anhydride are loaded. This mixture is stirred and circulated in a loop on the fixed bed.

The reaction medium is then heated using a thermostated bath, so as to have a constant temperature of 90 ° C., at the top of the catalytic bed.

It is left under these conditions by recirculating the reaction mixture on the fixed bed for 5 hours.

By analysis by vapor phase chromatography, a conversion rate of veratrole (TT) of 17% and a yield of acetoveratrole (RR) of 32% are determined.

Example 5

In a 100 ml reactor, 44.2 g (0.32 mol) of veratrole, 16.4 g (0.161 mol) of acetic anhydride and 0.13 g (0.0008 mol) of Anhydrous FeCl3.

The mixture is stirred for 30 min without heating. The internal temperature rises to 30 ° C.

The reaction is continued for 2.5 hours with stirring and heating to 110 ° C.

The reaction product thus obtained contains, according to the analysis by gas chromatography: 26.1 g of unreacted veratrole and 24.1 g of acetoveratrole, which corresponds to a yield of 83%.

The acetoveratrole obtained is recovered in a conventional manner, hydrolysis of the reaction medium, separation of the aqueous and organic phases and distillation from the organic phase.

Eîace_2

Hydrogenation of acetoveratrole.

50 g of acetoveratrole and 100 g of 96% ethyl alcohol are introduced into a 300 ml stainless steel reactor.

1.5 g of Raney Nickel are added to the solution. The reactor is purged with a stream of nitrogen and then with 2 x 10 bar of hydrogen.

The reactor is then placed under 10 bar of hydrogen, stirred and heated to 70 ° C.

The pressure in the reactor is kept constant at 10 bar throughout the reaction.

It is left under these conditions another 15 min after stopping the consumption of hydrogen.

The reactor is then purged with 2 x 10 bar of nitrogen. The catalyst is filtered.

The solvent is then distilled.

49.8 g of a pale yellow oil are recovered.

By analysis by vapor phase chromatography, a conversion rate of acetoveratrole (TT) of 100% and a yield of 1- (3,4-dimethoxyphenyDethanol (RR) of 98% are determined.

Etherification Examples 1 to 5

The etherification reaction is carried out, using different zeolitic catalysts which are zeolites in acid form.

In Examples 1 and 2, zeolites sold by the company PQ are used: a HY CBV 400 zeolite with an Si / Ai ratio of 2.6 (Example 1) and a HY CBV 760 zeolite with an Si / Ai ratio of 25 (example 2).

In Examples 3 and 4, H-mordenite type zeolites are used: H-mordenite 20A with Si / Ai ratio of 10 (example 3) and H-mordenite 90 A with Si / Ai ratio of 45 (example 4 ).

In Example 5, an H-β CBV 811 zeolite sold by the company PQ with an Si / Ai ratio of 12.5 is used.

100 g 1- (3,4-dimethoxyphenyl) ethanol and 120 g of 2-butyne-1-ol are introduced into a stirred reactor.

Stir and add 30 g of a zeolitic catalyst.

It is heated to 80 ° C.

After 4 hours of reaction, the reaction is finished.

The catalyst is filtered.

By assay by vapor phase chromatography, the following results are obtained, mentioned in table (I).

The excess 2-butyne-1-ol is recovered by distillation.

EXAMPLES 6 TO 10

The procedure of Examples 1 to 5 is reproduced, but using 200 g of 2-butyne-1-ol.

The results obtained are as follows:

Claims

1 - Process for the preparation of a benzyl ether from an aromatic compound characterized in that it consists: - in a first step, in carrying out the acylation of an aromatic compound by reaction of said aromatic compound with an acylating agent, in the presence of an effective amount of a zeolite or of a Friedel-Crafts catalyst leading to a ketone compound,

in a second step, performing the reduction of the carbonyl group to the carbinol group leading to a benzyl type alcohol,

- In a third step, to carry out the etherification of the hydroxyl group, by reaction of the alcohol of the benzyl type with another alcohol, in the presence of an effective amount of a zeolite.

2 - Process according to claim 1 characterized in that the aromatic compound corresponds to the general formula (I):

in which: - A symbolizes the remainder of a cycle forming all or part of a carbocyclic or heterocyclic, aromatic, monocyclic or polycyclic system: said cyclic residue being able to carry a group R representing a hydrogen atom or one or more substituents, identical or different,

- n represents the number of substituents on the cycle.

3 - Method according to one of claims 1 and 2 characterized in that the aromatic compound corresponds to the general formula (I) in which the residue A, optionally substituted, represents the rest:

1 ° - of an aromatic, monocyclic or polycyclic carbocyclic compound. 2 ° - of a heterocyclic aromatic, monocyclic or polycyclic compound. 3 ° - of a compound constituted by a chain of cycles, as defined in paragraphs 1 and / or 2 linked together:

. by a valential link,

. by one of the following groups: -o-, -CO-, -COO-, -OCOO

s-, -so-, -so ₂ -,

N-, -CO-N-,

1 1

^R o ^R o in these formulas, R _Q represents a hydrogen atom or an alkyl group having from 1 to 4 carbon atoms, a cyclohexyl or phenyl group.

4 - Method according to one of claims 1 to 3 characterized in that the aromatic compound corresponds to the general formula (I) in which the group or groups R, identical or different, represent one of the following groups:. a hydrogen atom,

. a linear or branched alkyl group preferably having from 1 to 6 carbon atoms and even more preferably from 1 to 4 carbon atoms,. a linear or branched alkenyl group preferably having from 2 to 6 carbon atoms and even more preferably from 2 to 4 carbon atoms,

. a linear or branched haloalkyl group preferably having from 1 to 6 carbon atoms and from 1 to 13 halogen atoms and even more preferably from 1 to 4 carbon atoms and from 1 to 9 halogen atoms,. a cycloalkyl group having 3 to 6 carbon atoms, preferably a cyclohexyl group,. a phenyl group,. a benzyl group,. a hydroxyl group,. a NO2 group,

. an alkoxy group R- O- or thioether R ^ -S- in which R- | represents a linear or branched alkyl group having from 1 to 6 carbon atoms and even more preferably from 1 to 4 carbon atoms or a phenyl group; an alkenyloxy group, preferably an allyloxy group,. a group - - (R2) 2 in which the identical or different R2 groups represent a hydrogen atom, a linear or branched alkyl group having from 1 to 6 carbon atoms and even more preferably from 1 to 4 carbon atoms or a phenyl group,

. a group -NH-CO-R2 in which the group R2 has the meaning given above,

. a carboxy group or an R2-O-CO- derivative in which the R2 group has the meaning given above,. an acyloxy or aroyloxy group R ^ -CO-O- in which the group Ri has the meaning given above,. a halogen atom, preferably a fluorine atom,. a CF3 group.

5 - Method according to one of claims 1 to 4 characterized in that the aromatic compound corresponds to the general formula (I) in which when n is greater than or equal to 2, two R groups and the 2 successive atoms of the aromatic ring may be linked together by an alkylene, alkenylene or alkenylidene group having from 2 to 4 carbon atoms to form a saturated, unsaturated or aromatic heterocycle having from 5 to 7 carbon atoms: one or more carbon atoms may be replaced by a another heteroatom, preferably oxygen or sulfur.

6 - Process according to claim 1 characterized in that the aromatic compound corresponds to the general formula (la):

in which :

- A symbolizes the remainder of a cycle forming all or part of a carbocyclic or heterocyclic, aromatic, monocyclic or polycyclic system: said cyclic residue being able to carry a group R representing a hydrogen atom or one or more electron donor substituents, identical or different,

- n represents the number of substituents on the cycle.

7 - Process according to claim 6 characterized in that the aromatic compound corresponds to the general formula (la) in which:

- the group or groups R, which are identical or different, represent one of the following groups:

an alkyl group, linear or branched, having from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, a linear or branched alkenyl group having from 2 to 6 carbon atoms, preferably from 2 to 4 carbon atoms, such as vinyl, allyl,

- a cyclohexyl, phenyl or benzyl group,

a linear or branched alkoxy group having from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms such as methoxy, ethoxy, propoxy, isopropoxy, butoxy groups, an alkenyloxy group, preferably an allyloxy group or a phenoxy group,

- a hydroxyl group,

a substituted amino group -N- (R ₂ ) 2 in which R2 has the meaning given above,

a linear or branched alkenyl group having from 2 to 6 carbon atoms, preferably from 2 to 4 carbon atoms, such as vinyl, allyl,

- a cyclohexyl, phenyl or benzyl group, - a linear or branched alkoxy group having from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms such as methoxy, ethoxy, propoxy, isopropoxy, butoxy groups, a group alkenyloxy, preferably an allyloxy group or a phenoxy group,

a hydroxyl group, a substituted amino group -N- (R2) 2 in which R2 has the meaning given above,

8 - Process according to claim 1 characterized in that the aromatic compound is an aromatic ether or thioether corresponding to the general formula (Y):

Y R '

in which : - Y represents an oxygen or sulfur atom,

A symbolizes the remainder of a cycle forming all or part of an aromatic, monocyclic or polycyclic carbocyclic system, system comprising at least one group YR ′: said cyclic residue being able to carry one or more substituents,

- R represents one or more substituents, identical or different,

- R 'represents a hydrocarbon group having from 1 to 24 carbon atoms, which can be an acyclic saturated or unsaturated, linear or branched aliphatic group; a saturated, unsaturated or aromatic, monocyclic or polycyclic cycloaliphatic group; a saturated or unsaturated, linear or branched aliphatic group, carrying a cyclic substituent,

- R 'and R can form a cycle optionally comprising another heteroatom,

- n is a number less than or equal to 4.

9 - Process according to claim 8 characterized in that the aromatic ether or thioether corresponds to the general formula () in which R 'represents:

- an acyclic, saturated or unsaturated, linear or branched aliphatic group, preferably a linear or branched alkyl group having from 1 to 12 carbon atoms, preferably from 1 to 6 carbon atoms: the hydrocarbon chain can possibly be interrupted by a heteroatom, a functional group and / or carrier of substituents,

an acyclic, saturated or unsaturated, linear or branched aliphatic group carrying an optionally substituted cyclic substituent: said acyclic group possibly being linked to the ring by a valential bond, a heteroatom or a functional group,

- a carbocyclic group saturated or comprising 1 or 2 unsaturations in the ring, generally having 3 to 8 carbon atoms, preferably 6 carbon atoms in the ring; said cycle being able to be substituted,

- an aromatic carbocyclic group, preferably monocyclic generally having at least 4 carbon atoms, preferably 6 carbon atoms in the ring; said cycle can be substituted.

10 - Method according to one of claims 8 and 9 characterized in that the ether or the aromatic thioether corresponds to the general formula (D in which R 'represents a linear or branched alkyl group having from 1 to 6 carbon atoms , preferably a methyl group, ethyl or a phenyl group. 11 - Method according to one of claims 8 to 10 characterized in that the aromatic ether or thioether corresponds to the general formula (Y) in which the residue A represents the remainder of an aromatic, monocyclic carbocyclic compound having at at least 4 carbon atoms and preferably 6 carbon atoms or the remainder of a polycyclic carbocyclic compound, preferably a naphthalene residue: the remainder A can carry one or more substituents on the aromatic nucleus.

12 - Method according to one of claims 8 to 11 characterized in that the ether or the aromatic thioether corresponds to formula (a):

in which: - n is a number less than or equal to 4, preferably equal to 0 or 1,

- Y represents an oxygen or sulfur atom,

. a hydrogen atom,

. a linear or branched alkyl group preferably having from 1 to 6 carbon atoms and even more preferably from 1 to 4 carbon atoms,

. a linear or branched alkenyl group preferably having from 2 to 6 carbon atoms and even more preferably from 2 to 4 carbon atoms,

. a linear or branched haloalkyl group preferably having from 1 to 6 carbon atoms and from 1 to 13 halogen atoms and even more preferably from 1 to 4 carbon atoms and from 1 to 9 halogen atoms,

. a cycloalkyl group having 3 to 6 carbon atoms, preferably a cyclohexyl group,. a phenyl group,

. a benzyl group,

. a hydroxyl group,. a NO2 group,

. an alkoxy group R _r O- or thioether R ^ -S- in which R- | represents a linear or branched alkyl group having from 1 to 6 carbon atoms and even more preferably from 1 to 4 carbon atoms or a phenyl group; an alkenyloxy group, preferably an allyloxy group,. a group -N- (R ₂ ) 2 in which the identical or different R2 groups represent a hydrogen atom, a linear or branched alkyl group having from 1 to 6 carbon atoms and even more preferably from 1 to 4 carbon atoms or a phenyl group,

. a group -NH-CO-R2 in which the group R2 has the meaning given above,

. a carboxy group or an R2-O-CO- derivative in which the R2 group has the meaning given above,. an acyloxy or aroyloxy group R ^ CO-O- in which the group R- | has the meaning given above,. a halogen atom, preferably a fluorine atom,. a CF ₃ group. - The groups R 'and R placed on two vicinal carbon atoms can form together and with the carbon atoms which carry them, a ring having 5 to 7 atoms, possibly including another heteroatom.

13 - Process according to claim 12 characterized in that the aromatic ether or thioether corresponds to formula (a) in which n is greater than or equal to 1, the groups R 'and R and the 2 successive atoms of the benzene ring can be linked together and form an alkylene, alkenylene or alkenylidene group having 2 to 4 carbon atoms to form a saturated, unsaturated or aromatic heterocycle having 5 to 7 atoms in which one or more carbon atoms can be replaced by a heteroatom, preferably oxygen or sulfur: the groups YR 'and R preferably forming a methylenedioxy, ethylenedioxy, methylenedithio or ethylenedithio group.

14 - Process according to claims 8 to 13 characterized in that the ether or the aromatic thioether corresponds to formula (Y) or (a) in which: - n is equal to 0 or 1,

R ′ represents an alkyl group, linear or branched, having from 1 to 6 carbon atoms or a phenyl group, preferably a methyl or ethyl group, - R represents an alkyl group, linear or branched, having from 1 to 6 carbon atoms, preferably a methyl or ethyl group; an alkoxy group, linear or branched, having from 1 to 4 carbon atoms, preferably a methoxy or ethoxy group. - The groups YR 'and R form a methylenedioxy, ethylenedioxy, methylenedithio or ethylenedithio group.

15 - Method according to one of claims 1 to 14 characterized in that the aromatic compound is benzene, toluene, isobutylbenzene, anisole, phenetole, veratrole, 1, 2-methylenedioxybenzene, 2 -methoxynaphthalene and thioanisole.

16 - Method according to one of claims 1 to 15 characterized in that the acylating agent is selected from carboxylic acids and their derivatives, halides or anhydrides, preferably anhydrides.

17 - Process according to claim 16 characterized in that the acylating agent corresponds to formula (II):

in which :

- R3 represents:

. a saturated or unsaturated, linear or branched aliphatic group having from 1 to 24 carbon atoms; a cycloaliphatic group, saturated, unsaturated or aromatic, monocyclic or polycyclic, having from 3 to 8 carbon atoms; a saturated or unsaturated, linear or branched aliphatic group, carrying a cyclic substituent,

- X 'represents:

. a halogen atom, preferably a chlorine or bromine atom,. a hydroxyl group,

. a group -O-CO-R4 with R4, identical or different from R3, having the same meaning as R ₃ : R3 and R ₄ can together form a divalent aliphatic saturated or unsaturated group, linear or branched, having at least 2 atoms of carbon.

18 - Process according to claim 17 characterized in that the acylating agent corresponds to formula (II) in which X 'represents an atom of chlorine and R represents a linear or branched alkyl group having from 1 to 12 carbon atoms, preferably 1 to 4 atoms: the hydrocarbon chain can possibly be interrupted by a heteroatom or by a functional group or carrier of substituents, preferably, halogen atoms, R3 also represents a phenyl group; X 'represents a group -O-CO-R4. in which R3 and R are identical and represent an alkyl group having from 1 to 4 carbon atoms optionally carrying halogen atoms or a phenyl group.

19 - Process according to claim 17 and 18 characterized in that the acylating agent is chosen from:

- acetic anhydride,

- propanoic anhydride,

- butyric anhydride,

- isobutyric anhydride,

- trifluoroacetic anhydride,

- benzoic anhydride.

- monochloroacetyl anhydride,

- dichloroacetic anhydride,

- acetyl chloride,

- monochloroacetyl chloride,

- dichloroacetic chloride,

- propanoyl chloride,

- isobutanoyl chloride,

- pivaloyl chloride,

- stearoyl chloride,

- crotonyl chloride,

- benzoyl chloride,

- chlorobenzoyl chlorides,

- p-nitrobenzoyl chloride

- methoxybenzoyl chlorides,

- naphthoyl chlorides,

- acetic acid,

- benzoic acid.

20 - Method according to one of claims 16 to 19 characterized in that the acylating agent is acetic anhydride, propanoic, benzoic, monochloroacetyl, dichloroacety, benzoyl chlorides. 21 - Process according to claim 1 characterized in that the zeolite is a synthetic zeolite chosen from:

- synthetic zeolites with a one-dimensional network such as zeolite ZSM-4, zeolite L, zeolite ZSM-12, zeolite ZSM-22, zeolite ZSM-

23, zeolite ZSM-48,

- zeolites with a two-dimensional network such as mordenite, ferrierite,

- zeolites with a three-dimensional network such as the zeolite β, the zeolite Y, the zeolite X, the zeolite ZSM-5, the zeolite ZSM-11, the offerite, - the mesoporous zeolite of MCM type.

22 - Process according to claim 21 characterized in that the zeolite is an H-mordenite, H-β or H-Y zeolite.

23 - Method according to one of claims 1, 21 and 22 characterized in that the zeolite is used alone or in admixture with an inorganic matrix chosen, preferably, from metal oxides, such as oxides of aluminum, silicon and / or zirconium, or also among clays and more particularly, kaolin, talc or montmorillonite.

24 - Method according to one of claims 1 to 23 characterized in that the amount of catalyst represents by weight relative to the aromatic compound involved, from 0.01 to 50%, preferably from 1.0 to 20%.

25 - Method according to one of claims 1 to 24 characterized in that the temperature at which the acylation reaction is carried out is between 20 ° C and 300 ° C, preferably between 40 ° C and 150 ° vs.

26 - Method according to one of claims 1 to 25 characterized in that the reaction mixture passes through the catalytic bed, preferably from bottom to top and at its outlet, is returned to the reagent mixing zone in order to be recycled a sufficient number of times to obtain the desired substrate conversion rate.

27 - The method of claim 26 characterized in that the conversion rate is greater than 20%, and preferably between 50 and 100%. 28 - Process according to claim 1 characterized in that the catalyst is a salt comprising an organic counterion, preferably acetate, propionate, benzoate, methanesulfonate, trifluoromethanesulfonate of the metallic or metalloid elements of the groups ( llla), (IVa), (VIII), (llb), (lllb), (IVb), (Vb) and (Vlb) of the Periodic Table of the Elements, preferably a rare earth or bismuth trifluoromethanesulfonate.

29 - Process according to claim 1 characterized in that the catalyst is a salt comprising an inorganic counterion, preferably chloride, bromide, iodide, sulfate, oxide and analogous products of the metallic or metalloid elements of the groups (Ma) , (llla), (IVa), (VIII), (llb), (lllb), (IVb), (Vb) and (Vlb) of the periodic table.

30 - Process according to claim 29 characterized in that the catalyst is chosen from metal halides and preferably magnesium chloride, aluminum chloride, aluminum bromide, ferric chloride, stannic chloride, trifluoride boron.

31 - Method according to one of claims 28 to 30 characterized in that the amount of catalyst is such that the ratio between the number of moles of catalyst and the number of moles of compound of formula (II) is preferably understood, between 0.001 and 2.0, and even more preferably between 0.05 and 1.0.

32 - Method according to one of claims 28 to 31 characterized in that the temperature at which the acylation reaction is carried out is between 20 ° C and 200 ° C, preferably between 40 ° C and 120 ° vs.

33 - Method according to one of claims 1 to 32 characterized in that the ketone compound obtains (III):

- in which R, R3, A and n have the meaning given previously in one of claims 2 to 7.

34 - Method according to one of claims 1 to 33 characterized in that the ketone compound corresponds to formula (III '): Y R '

- in which R, R ', R3, Y, A and n have the meaning given previously in one of claims 8 to 11, 14.

35 - Method according to one of claims 1 to 34 characterized in that the ketone compound corresponds to the formula (IIIa):

- in which R, R ', R ₃ , Y and n have the meaning given previously in one of claims 12 to 14.

36 - Method according to one of claims 1, 32 to 35 characterized in that the hydrogenation of the ketone compound is carried out, in the presence of a catalyst based on a metal from group VIII of the periodic table, preferably a noble metal, cobalt or nickel.

37 - Process according to claim 36 characterized in that the hydrogenation catalyst is Raney nickel.

38 - Method according to one of claims 36 and 37 characterized in that the temperature at which the hydrogenation reaction is carried out is chosen between 50 ° C and 120 ° C, preferably between 60 ° C and 100 ° C.

39 - Method according to one of claims 36 to 38 characterized in that the hydrogenation is carried out in the liquid phase, in the presence or not of an organic solvent.

40 - Method according to one of claims 1 to 39 characterized in that the alcohol of benzyl type (IV):

41 - Method according to one of claims 1 to 40 characterized in that the benzyl type alcohol obtained corresponds to formula (IV):

42 - Method according to one of claims 1 to 41 characterized in that the alcohol of benzyl type (IVa):

- in which R, R3 and n have the meaning given previously in one of claims 12 to 14.

43 - Method according to one of claims 1, 32 to 35 characterized in that one carries out an enantioselective hydrogenation of the ketone compound, in the presence of a metal complex comprising an optically active diphosphine.

44 - Process according to claim 43 characterized in that the optically active diphosphine is BINAP or else BIPNOR [bis- (1-phospha-2,3-diphenyl-4,5-dimethylnorbomadiene)].

45 - Method according to one of claims 1, 40 to 44 characterized in that the etherification of the benzyl alcohol is carried out by reacting it with another alcohol, in the presence of an effective amount of 'a zeolite.

46 - Process according to claim 45 characterized in that the benzyl alcohol is chosen from:

- vanillic alcohol,

- p-hydroxybenzyl alcohol,

- 1- (4-hydroxy-3-methoxyphenyl) ethanol, - 2-hydroxybenzyl alcohol,

- p-methoxybenzyl alcohol,

- 3,4-dimethoxybenzyl alcohol,

- 6-n-propyl-3,4-dimethoxybenzyl alcohol, - alcohol (3,4-dimethoxyphenyl) dimethylcarbinol,

- alcohol 1 (3,4-dimethoxyphenyl) ethanol,

- 1 - [1-hydroxy-2-methylpropyl] -3,4-dimethoxybenzene,

- 1- [1-hydroxy-2-methylpropyl] -3,4-diethoxybenzene,

- 1- [1-hydroxyethyl] -3,4-diethoxybenzene, - 1 - [1-hydroxyethyl] -3,4-dimethoxy-6-propylbenzene,

- 5- [1-hydroxyethyl] -1,3-benzodioxol,

- naphthalene-2-methylol.

47 - Method according to one of claims 45 and 46 characterized in that the alkanol used corresponds to the general formula (V):

R ₅ - OH (V) in said formula (V):

- R5 represents a hydrocarbon group having from 1 to 24 carbon atoms, which can be a saturated or unsaturated, linear or branched acyclic aliphatic group; a saturated, unsaturated or aromatic cycloaliphatic group; a saturated or unsaturated, linear or branched aliphatic group, carrying a cyclic substituent.

48 - Process according to claim 47 characterized in that the alkanol corresponds to formula (V) in which R ₅ represents:

an acyclic, saturated or unsaturated, linear or branched aliphatic group, preferably a linear or branched alkyl, alkenyl, alkadienyl, alkynyyl group preferably having from 1 to 24 carbon atoms: the hydrocarbon chain can possibly be interrupted by functional group and / or carrier of substituents

- an acyclic, saturated or unsaturated, linear or branched aliphatic group carrying an optionally substituted cyclic substituent: said acyclic group possibly being linked to the ring by a valential bond, a heteroatom or a functional group, - a saturated carbocyclic group or comprising 1 or 2 unsaturations in the ring, generally having 3 to 7 carbon atoms, preferably 6 carbon atoms in the ring; said cycle can be substituted. 49 - Method according to one of claims 47 and 48 characterized in that the alkanol is a terpene alcohol of formula (Va):

T - OH (Va) in said formula (Va): - T represents the remainder of a terpene alcohol having a number of carbon atoms multiple of 5.

50 - Method according to claim 49 characterized in that the terpene alcohol used corresponds to the general formula (Va) in which the remainder T represents a hydrocarbon group having from 5 to 40 carbon atoms and more particularly an aliphatic group , saturated or unsaturated, linear or branched; a cycloaliphatic, saturated, unsaturated or aromatic, monocyclic or polycyclic group, comprising rings having from 3 to 8 carbon atoms.

51 - Method according to one of claims 49 and 50 characterized in that the remainder T represents the remainder:

- an aliphatic, saturated or unsaturated, linear or branched terpene alcohol,

52 - Process according to claim 47 characterized in that the alcohol of formula (V) is chosen from:

. methanol,

. ethanol,

. trifluoroethanol,

. propanol, isopropyl alcohol,. butanol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol,

. pentanol, isopentyl alcohol, dry pentyl alcohol and tert-pentyl alcohol,

. propargyl alcohol,. 3-chlorobut-2-en-1-ol,

. 2-butyn-1-ol,

. 3,7-dimethyloct-6-en-1-ol,

. chrysanthemum alcohol,

. 3,7-dimethyloctanol,. geraniol,. the linalool,. citronellol,. hydoxycitronellol,

. nerol,. thymol,. menthol,. isobomeol,. verbenol.

53 - Method according to one of claims 45 to 52 characterized in that the catalyst is a synthetic zeolite described in one of claims 21 to 23.

54 - Method according to one of claims 45 to 53 characterized in that the ratio between the number of moles of alkanol and the number of moles of benzyl alcohol varies between 1 and 30.

55 - Method according to one of claims 45 to 54 characterized in that the amount of catalyst represents by weight relative to the reactant in default, from 2 to 50%, preferably from 5 to 20%.

56 - Method according to one of claims 45 to 55 characterized in that the temperature at which the etherification reaction is carried out is between 50 ° C and 200 ° C, preferably between 50 ° C and 100 ° vs.

57 - Method according to one of claims 45 to 56 characterized in that the residence time of the material flow on the catalytic bed varies between 15 min and 10 h, and preferably between 30 min and 5 h.

58 - Method according to one of claims 45 to 57 characterized in that one obtains at the end of the reaction, a liquid phase comprising alcohol of the etherified benzyl type which can be recovered in conventional manner.

59 - Method according to one of claims 1 to 58 characterized in that the etherified benzyl type alcohol obtained corresponds to formula (VI):

- in which R, R3, R5, A and n have the meaning given previously described in one of claims 2 to 7, 17, 18, 47 to 52.

60 - Method according to one of claims 1 to 59 characterized in that the etherified benzyl type alcohol obtained corresponds to formula (VI '):

- in which R, R ', R ₃ , R ₅ , Y, A and n have the meaning given previously described in one of claims 8 to 11, 14, 17, 18, 47 to 52.

61 - Method according to one of claims 1 to 60 characterized in that the benzyl type alcohol formula (Via):

- in which R, R3, R5 and n have the meaning given previously described in one of claims 12 to 14, 17, 18, 47 to 52.