[go: up one dir, main page]

CA2084587A1 - Process for the preparation of trifluorobenzene derivatives - Google Patents

Process for the preparation of trifluorobenzene derivatives

Info

Publication number
CA2084587A1
CA2084587A1 CA002084587A CA2084587A CA2084587A1 CA 2084587 A1 CA2084587 A1 CA 2084587A1 CA 002084587 A CA002084587 A CA 002084587A CA 2084587 A CA2084587 A CA 2084587A CA 2084587 A1 CA2084587 A1 CA 2084587A1
Authority
CA
Canada
Prior art keywords
nitro
c8alkyl
trifluorobenzoic acid
formula
trifluoronitrobenzene
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
CA002084587A
Other languages
French (fr)
Inventor
Henry Szczepanski
Urs Burckhardt
Alfons Pascual
Saleem Farooq
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Novartis AG
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of CA2084587A1 publication Critical patent/CA2084587A1/en
Abandoned legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21C—NUCLEAR REACTORS
    • G21C3/00—Reactor fuel elements and their assemblies; Selection of substances for use as reactor fuel elements
    • G21C3/02—Fuel elements
    • G21C3/04—Constructional details
    • G21C3/06—Casings; Jackets
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C201/00—Preparation of esters of nitric or nitrous acid or of compounds containing nitro or nitroso groups bound to a carbon skeleton
    • C07C201/06—Preparation of nitro compounds
    • C07C201/08—Preparation of nitro compounds by substitution of hydrogen atoms by nitro groups
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C201/00—Preparation of esters of nitric or nitrous acid or of compounds containing nitro or nitroso groups bound to a carbon skeleton
    • C07C201/06—Preparation of nitro compounds
    • C07C201/12—Preparation of nitro compounds by reactions not involving the formation of nitro groups
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C205/00—Compounds containing nitro groups bound to a carbon skeleton
    • C07C205/13—Compounds containing nitro groups bound to a carbon skeleton the carbon skeleton being further substituted by hydroxy groups
    • C07C205/26—Compounds containing nitro groups bound to a carbon skeleton the carbon skeleton being further substituted by hydroxy groups and being further substituted by halogen atoms
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C205/00—Compounds containing nitro groups bound to a carbon skeleton
    • C07C205/27—Compounds containing nitro groups bound to a carbon skeleton the carbon skeleton being further substituted by etherified hydroxy groups
    • C07C205/35—Compounds containing nitro groups bound to a carbon skeleton the carbon skeleton being further substituted by etherified hydroxy groups having nitro groups and etherified hydroxy groups bound to carbon atoms of six-membered aromatic rings of the carbon skeleton
    • C07C205/36—Compounds containing nitro groups bound to a carbon skeleton the carbon skeleton being further substituted by etherified hydroxy groups having nitro groups and etherified hydroxy groups bound to carbon atoms of six-membered aromatic rings of the carbon skeleton to carbon atoms of the same non-condensed six-membered aromatic ring or to carbon atoms of six-membered aromatic rings being part of the same condensed ring system
    • C07C205/37—Compounds containing nitro groups bound to a carbon skeleton the carbon skeleton being further substituted by etherified hydroxy groups having nitro groups and etherified hydroxy groups bound to carbon atoms of six-membered aromatic rings of the carbon skeleton to carbon atoms of the same non-condensed six-membered aromatic ring or to carbon atoms of six-membered aromatic rings being part of the same condensed ring system the oxygen atom of at least one of the etherified hydroxy groups being further bound to an acyclic carbon atom
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C205/00—Compounds containing nitro groups bound to a carbon skeleton
    • C07C205/49—Compounds containing nitro groups bound to a carbon skeleton the carbon skeleton being further substituted by carboxyl groups
    • C07C205/57—Compounds containing nitro groups bound to a carbon skeleton the carbon skeleton being further substituted by carboxyl groups having nitro groups and carboxyl groups bound to carbon atoms of six-membered aromatic rings of the carbon skeleton
    • C07C205/59—Compounds containing nitro groups bound to a carbon skeleton the carbon skeleton being further substituted by carboxyl groups having nitro groups and carboxyl groups bound to carbon atoms of six-membered aromatic rings of the carbon skeleton the carbon skeleton being further substituted by singly-bound oxygen atoms
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21C—NUCLEAR REACTORS
    • G21C7/00—Control of nuclear reaction
    • G21C7/02—Control of nuclear reaction by using self-regulating properties of reactor materials, e.g. Doppler effect
    • G21C7/04—Control of nuclear reaction by using self-regulating properties of reactor materials, e.g. Doppler effect of burnable poisons
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21C—NUCLEAR REACTORS
    • G21C7/00—Control of nuclear reaction
    • G21C7/06—Control of nuclear reaction by application of neutron-absorbing material, i.e. material with absorption cross-section very much in excess of reflection cross-section
    • G21C7/22—Control of nuclear reaction by application of neutron-absorbing material, i.e. material with absorption cross-section very much in excess of reflection cross-section by displacement of a fluid or fluent neutron-absorbing material, e.g. by adding neutron-absorbing material to the coolant
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E30/00—Energy generation of nuclear origin
    • Y02E30/30—Nuclear fission reactors

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Plasma & Fusion (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

ABSTRACT

Process for the preparation of trifluorobenzene derivatives Disclosed is a process for the preparation of trifluoronitrobenzene derivatives of formula (I) wherein R is hydrogen, C1-C8alkyl, halo-C1-C8alkyl or allyl, as well as a process for the preparation of 2-nitro-3,4,6-trifluorobenzoic acid derivatives of formula II

(II) wherein R is as defined above.

The compounds of formula I are useful intermediates for the synthesis of pest control agents.

Description

208~587 Process for the preparation of trifluorobenzene derivatives The present invention relates to a novel process for the preparation of 2,3,~-trifluoro-nitrobenzene derivatives and to novel interrnediates.

Specifically, the invention relates tc a process for the preparation of2,3,5-trifluoronitrobenzene derivatives of formula Ro~b, ~,J~ (I), F ~ No2 wherein R is hydrogen, Cl-C8alkyl, halo-C~-C8alkyl or allyl.

The compounds of formula I are useful intermediates for the synthesis of highly active insecticides and acaricides of the class of the benzoyl ureas. These compounds are disclosed in EP-A-327 504. However, too low a yield and the formation of by-products make the process disclosed in this publication poorly suited to the large-scale production of the required intermediate. There is therefore a need to provide a more suitable route of synthesis for the preparation of the compounds of formula I. Surprisingly, this need is substantially fulfilled by the proposed novel process of this invention.

In the definition of formula I above, alkyl is ~ypically methyl, ethyl, propyl, isopropyl, butyl and the isomers thereof, amyl, isoamyl or n-octyl.

The suitable Cl-C8alkyl groups which are substituted by one or more than one halogen atom may be partially or also perhalo~enated, and the alkyl moieties are as defined above.
Halogen is typically fluoro, chloro, bromo or iodo. Suitable examples of such substituents include CF3, ethyl which is substituted by one to five fluorine, chlorine and/or bromine atoms, typically CHFCF3, CF2CF3, CF2CCI3, CF2CHCI2, CF2CHF2, CF2CFCl2, CF2CHBr2, CF2CHCIF, CH2CF3, CF2CH2Cl, CF2CHBr2, CFCICFCI, CF2CHBrF or CCIFCHCIF; propyl or isopropyl which is substituted by one to seven fluorine, chlorine and/or bromine atoms, typically CF2CHBrCH2Br, CF2CHFCF3, CHFCF2CF3, CF2CF2CF3, CH2CF2CF3 or CHFCF2CF3; butyl or an isomer thereof which is substituted by one to nine fluorine, chlorine and/or bromine atoms, typically CHFCF2CHFCF3, (CF2)3CF3 or CH2CF2CF2CF3.

Some of the trifluoronitrobenzene derivatives of formula I prepared by the process of ~his invention are known. They are use~ul intermediates for the synthesis of chemical agents that have a pronounced insecticidal and acaricidal activity. Typical examples of such compounds are:

N-2,6-difluorobenzoyl-N'-(4-ethoxy-2,3,5-trifluorophenyl)-urea, N-2,6-difluorobenzoyl-N'-(4-isopropoxy-2,3,5-trifluorophenyl)-urea, N-2,6-difluorobenzoyl-N'-[4-(2-chloro- 1,1 ,2-trifluoroethoxy)-2,3,5-trifluorophenyl]-urea, N-2,6-difluorobenzoyl-N'-(4-tert-butoxy-2,3,5-trifluorophenyl)-urea, N-2,6-difluorobenzoyl-N'-~4-(1 ,1 ,2,2-tetrafluoroethoxy)-2,3,5-trifluorophenyl]-urea, N-2,6-difluorobenzoyl-N'[4-(1,1,2,3,3,3-hexafluoropropoxy)-2,3,5-trifluoro]phenyl-urea, N-2,6-difluorobenzoyl-N'-(4-trifluoromethoxy-2,3,5-trifluorophenyl)-urea, N-2,6-difluorobenzoyl-N'-(4-heptafluoropropoxy-2,3 ,5-trifluorophenyl)-urea, N-2,6-difluorobenzoyl-N'-(4-nonafluorobutoxy-2,3,5-trifluorophenyl)-urea, N-2,6-difluorobenzoyl-N'-14-(2,2,2-trifluoroethoxy)-2,3,5-trifluorophenyl]-urea, , N-2,6-difluorobenzoyl-N'-[4-(2,2-dibromo- 1 ,1-difluoroethoxy)-2,3,5-trifluorophenyl]-urea, N-2,6-difluorobenzoyl-N'-[4-(1,2-dichloro-1,2-difluoroethoxy)-2,3,5-trifluorophenyl]-urea, N-2,6-difluorobenzoyl-N'-[4-(2-chloro- 1,1-difluoroethoxy)-2,3,5-trifluorophenyl]-urea, N-2,6-difluorobenzoyl-N'-[4-(2,2,3,3,3-pentafluoropropoxy)-2,3,5-trifluorophenyll-urea, N-2,6-difluorobenzoyl-N'-[4-(heptafluoropropoxy)-2,3,5-trifluorophenyl]-utea, N-2,6-difluorobenzoyl-N'-[4-(2,2,3,3,4,4,4-heptafluorobutoxy)-2,3,5-trifluorophenyl]--urea, N-2,6-difluorobenzoyl-N'-[4-(nonafluorobutoxy)-2,3,5-trifluorophenyl]-urea, and N-2-chloro-6-fluorobenzoyl-N'-~4-(1,1,2,3,3,3-hexafluoropropoxy)-2,3,5-trifluorophenyl]--urea.

The invention postulates the preparation of 2,3,5-trifluoronitrobenzene derivatives of 208~587 formula R--o~

F ~NO~

wherein R is hydrogen, Cl-C8alkyl, halo-CI-C8alkyl or allyl, by decarboxylating a 3,4,6-trifluoro-2-nitrobenzoic acid of formula II

R--~D~cH
,l~' Jl~ (Il), F ~ NO2 wherein R is hydrogen, Cl-C8alkyl, halo-CI-C8alkyl or allyl, or a salt thereof.

The decarboxylation is conveniently carried out either a) in the presence of a base; or b) in an organic solvent, in a mixture of an organic solvent and water or in water; or c) in the temperature range from +50 to +2S0C.

A particularly preferred embodiment of the inventive process comprises carrying out the decarboxylation in an organic solvent, in a mixture of an organic solvent and water or in water; in the presence of a base and in the temperature range from +50 to +250C.

Suitable solvents for the decarboxylation reaction (lI_I) of the inventive process are in particular sulfoxides such as dimethyl sulfoxide or sulfolane: amides such as formamide, dimethyl formamide, N-methylacetamide or dimethyl acetamide; N-methylpyrrolidone;
alcohols such as n-butanol, isobutanol, n-amyl alcohol, n-octanol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether or diethylene glycol dimethyl ether; tetramethylurea; aromatic hydrocarbons such as toluene or xylene;
halogenated aromatic hydrocarbons such as chlorobenzene or 1,2-dichlorobenzene;
nitrobenzene; tetrahydronaphthalene; decalin; heterocyclic solvents such as pyridine or quinoline.

Suitable bases are inorganic as well as organic bases. Preferred inorganic bases include carbonates such as sodium carbonate, sodium hydrogencarbonate or potassium carbonate;
phosphates such as sodium phosphate or sodium hydrogenphosphate; sodium hydroxide;
potassium hydroxide, calcium hydroxide or magnesium hydroxide.

Organic bases typically include secondary and tertiary amines, preferably triethylamine, triisopropanolamine, triethanolamine, tripropylamine, tributylamine, N,N-dimethyl-benzylamine, diisopropylamine and N,N-dimethylaniline; alcoholates such as sodium methylate, sodium ethylate or potassium tert-butylate; as well as pyridine.

A particularly preferred process, however, comprises carrying out the decarboxylation in dimethyl sulfoxide, in the presence of triethylamine and in the temperature range from +80C to +140C.

The decarboxylation of this invention can be carried out with the free phenol of formula HO~ COOH
ll (lla) F ~NO2 as well as with the etherified compound R O~COOH
ll (lIb), F~No2 .~ 2084~7 -s wherein R' is C~-C8alkyl, halo-CI-C8aLlcyl or allyl.

The decarboxylation of the compound of formula IIa gives a phenol of subformula Ia HO~

F ~ N2 (Ia) which, if desired, can be converted by etherification into a compound of formula R~

F ~N2 (Ib), wherein R' has the same meaning as in IIb.

Alternatively, the free nitrophenol la can be prepared by decarboxylating an etherified carboxylic acid of formula Ub and converting the intermediate Ib by ether cleavage into the free phenol of formula Ia.

The etherification reactions (Ia ,Ib) are carried out by methods known in the literature, suitable alkylating agents being typically alkyl halides such as methyl chloride, methyl bromide, methyl iodide, ethyl chloride, ethyl bromide or ethyl iodide, or tert-butyl chloride; iodofluorocarbons such as CF3CF2I or CF3CF2CF2I; alkenes such as ethylene, propene, 2-butene or isopropene; alkyl sulfates such as dimethyl sulfate or diethyl sulfate;
halogenated alkenes such as tetrafluoroethene, hexafluoropropene or chlorotrifluoro-ethane; chlorofluoroalkyls such as CF2CI2, CF2CIF, CIFCH-CF2-CF3 or ClFCH-(CF2)s-CF3; and allyl chloride, allyl bromide or allyl iodide.

The ether cleavage (Ib_Ia) is also carried out by methods known per se, typically in the presence of strong mineral acids such as hydriodic acid and hydrobromic acid.

-~\ 208~87 The compounds of formula I that have not yet been described in the literalure, wherein R
is halo-CI-C8alkyl or allyl, are also an object of the present invention. These compounds are in particular:
4-(1, 1 ,2,3,3,3-hexafluoropropoxy)-2,3,5-trifluoronitrobenzene, 4-(1, 1 ,2,2-tetrafluoroethoxy)-2,3,5-trifluoronitrobenzene, 4-(2-chloro- 1,1 ,2-trifluoroethoxy)-2,3,5-trifluoronitrobenzene, 4-(1 ,2,3,3,3,-pentafluoropropoxy)-2,3,5-trifluoronitrobenzene, 4-heptafluoropropoxy-2,3 ,5-trifluoronitrobenzene, 4-(2,2,2-trifluoroethoxy)-2,3,5-trifluoronitrobenzene, 4-(2,2-dibromo-1,1-difluoroethoxy)-2,3,5-trifluoronitrobenzene, 4-(1,2-dichloro-1,2-difluoroethoxy)-2,3,5-trifluoronitrobenzene, 4-(2-chloro-1,1-difluoroethoxy)-2,3,5-trifluoronitrobenzene, 4-(2,2,3,3,3-pentafluoropropoxy)-2,3,5-trifluoronitrobenzene, 4-(2,2,3,3,4,4,4-heptafluorobutoxy)-2,3,5-trifluoronitrobenzene, 4-nonafluorobutoxy-2,3,5-trifluoronitrobenune, 4-trifluoromethoxy-2,3,5-trifluoronitrobenzene and 4-chlorodifluoromethoxy-2,3 ,5-trifluoronitrobenzene.

The invention further relates to a process for the preparation of 2-nitro-3,4,6-trifluorobenzoic acid derivatives of formula (II), which comprises reacting a 2,4,5-trifluorobenzoic acid derivative of formula F

RO~,~COOH
,l~ 1~ (III), F

wherein R is hydrogen, Cl-C8alkyl, halo-C2-Cxalkyl or allyl, with a nitrating agent.

The nitration (III_II) is carried out by methods which are known in the literature, preferably in the presence of an organic solvent, in the absence or presence of a solvent.

Suitable nitrating agents are the reagents commonly used for such reactions, typically nitric acid, N203, N204, N20s, alkali metal nitrates such as KNO3 or NaNO3, AgNO3, alkyl nitrates such as ethyl or butyl nitrate and nitronium salts such as NO2BF4 or 208~58~

NO2CF3SO3.

Particularly suitable solvents are halogenated hydrocarbons such as chloroform, methylene chloride, 1,2-dichloroethane, l,l,l-trichloroethane or 1,1,2-trichloroethane;
nitromethane; nitrobenzene; halogenated aromatic hydrocarbons such as chlorobenzene or ortho-dichlorobenzene; ethers such as diethyl ether, di-n-butyl ether, tert-butyl methyl ether, tetrahydrofuran, dioxane or ethylene glycol dimethyl ether, and water, as well as mixtures of different solvents. Particularly preferred solvents are, on the one hand, halogenated hydrocarbons, preferably chloroform, and, on the other, water.

It is preferred to add the usual acids in the nitration reactions carried out in the practice of this invention, typically sulfuric acid, perchloric acid, methanesulfonic acid, trifluoromethanesulfonic acid or phosphoric acid; and also Lewis acids such as FeC13, BF3, AIC13 or SnC14. However, a process in which the nitration is carried out with nitrating acid, most especially only with nitric acid, is very particularly preferred.

Alternatively, procedures are preferred in which the nitration is carried out a) in the temperature range from 0C to 60C, or b) with nitric acid, in the presence of a solvent and in the temperature range from 0C to 60C; or c) with nitric acid, in chloroform and in the temperature range from +10C to +50C.

In the synthesis of the compounds of formula II the following process variants may be carried out:
A) 3-hydroxy-2,4,5-trifluorobenzoic acid of formula HO~COOH
J !1 (IlIa) F ~

can be converted by nitration into 5-hydroxy-2-nitro-3,4,6-trifluorobenzoic acid of formula IIa, which can then be etherified to give the compound of formula IIb, or B) a compound of formula B~ a compound of formula F .
R'~D~CH
11 tmb).
F~
F

wherein R' is C~-C8aL~cyl, halo-CI-C8aLkyl or allyl, can be converted by nitration into a compound of formual IIb which, if desired, can be converted by ether cleavage into 5-hydroxy-2-nitro-3,4-6-trifluorobenzoic acid of formula IIa.

The etherification reactions (IIa_IIb) can be carried out by methods which are known in the literature, suitable aL~ylating agents being typically aLkyl halides such as methyl chloride, methyl bromide, methyl iodide, ethyl chloride, ethyl bromide or ethyl iodide, or tert-butyl chloride; iodofluorocarbons such as CF3CF2I or CF3CF2CF2I; alkenes such as ethylene, propene, 2-butene or isopropene; alkyl sulfates such as dimethyl sulfate or di-ethyl sulfate; halogenated alkenes such as tetrafluoroethene, hexafluoropropene or chloro-trifluoroethene; as well as chlorofluorocarbons such as CF2Cl2, CF3CI, ClFCH-CF2-CF3 or ClFCH-(CF2)s-CF3; and allyl chloride, allyl bromid or allyl iodide.

The ether cleavage (IIb_IIa) is also carried out by methods known per se, typically in the presence of a strong mineral acid such as hydriodic acid or hydrobromic acid.

The compounds of formula F O
RO ~OH

F J~ NO2 wherein R is hydrogen, Cl-C8alkyl, halo-CI-C8alkyl or allyl, and the salts thereof, are novel and likewise constitute an object of the present invention. Preferred individual compounds of this group are:

2084~87 5-methoxy-2-nitro-3,4,6-trifluorobenzoic acid, 5-ethoxy-2-nitro-3,4,6-trifluorobenzoic acid, 5 propoxy-2-nitro-3,4,6-trifluorobenzoic acid, 5-isopropoxy-2-nitro-3,4,6-trifluorobenzoic acid, 5-butoxy-2-nitro-3,4,6-trifluorobenzoic acid, 5-tert-butoxy-2-nitro-3,4,6-trifluorobenzoic acid, 5-(1,1,1,2,3,3,3-hexafluoropropoxy)-2-nitro-3,4,6-trifluorobenzoic acid, 5-(1,1,2,2-tetrafluoroethoxy)-2-nitro-3,4,6-trifluorobenzoic acid, 5-(2-chloro-1,1,2-~rifluoroethoxy)-2-nitro-3,4,6-trifluorobenzoic acid, 5-heptafluoropropoxy-2-nitro-3,4,6-trifluorobenzoic acid, 5-(1,2,3,3,3-pentafluoropropoxy)-2-nitro-3,4,6-trifluorobenzoic acid, 5-(2,2,2-trifluoroethoxy)-2-nitro-3,4,6-trifluorobenzoic acid, 5-(2,2-dibromo-1,1-difluoroethoxy)-2-nitro-3,4,6-trifluorobenzoic acid, 5-(1,2-dichloro-1,2-difluoroethoxy)-2-nitro-3,4,6-t;ifluorobenzoic acid, 5-(2-chloro-1,1-difluoroethoxy)-2-nitro-3,4,6-trifluorobenzoic acid, 5-(2,2,3,3,3-pentafluoropropoxy)-2-nitro-3,4,6-trifluorobenzoic acid, 5-(2,2,3,3,4,4,4-heptafluorobutoxy)-2-nitro-3,4,6-trifluorobenzoic acid, 5-nonafluorobutoxy-2-nitro-3,4,6-trifluorobenzoic acid, and 5-allyloxy-2-nitro-3,4,6-trifluorobenzoic acid, and the salt~. thereof.

2-Nitro-5-hydroxy-3,4,6-trifluorobenzoic acid, and the salts thereof, are especially preferred.

Salts of the compound of formula II will be understood, on the one hand, as meaning alkali metal and alkaline earth metal salts, i.e. in par~icular the lithium, sodium, potassium magnesium and calcium salts, also the aluminium sal.s, the salts with transition metals such as Fe, Mn, Co, Ni, Cu, and Zn, as well as NH4~3 salts.

On the other hand, the salts are salts with organic cations. These cations include in particular organic ammonium ions such as triethylammonium, tributylammonium, tripropylammonium, t;iisopropylammonium, tetramethylammonium, tetraethyl-ammonium, tetrabutylammonium or t;imethylbenzylammonium. Further, N,N-diaL"ylated anilines such as N,N-dimethylanilinium can serve as as counterions.

2084~87 Some of the compounds of formula III are known (EP-A 271 275, EP-A-352 123). They are compounds of formula III, wherein R is hydrogen, Cl-C4alkyl or halomethyl. Typical examples of other novel starting compounds required for the process of this invention are:
3-isoamyloxy-2,4,5-trifluorobenzoic acid, 3-octyloxy-2,4,5-tri~luorobenzoic acid, 3-(1,1,2,2-tetrafluoroethoxy)-2,4,5-trifluorobenzoic asid, 3-(2-chloro-1,1,2-trifluoroethoxy)-2,4,5-trifluorobenzoic acid, 3-(1,1,1,2,3,3,3-hexafluoropropoxy)-2,4,5-trifluorobenzoic acid, 3-(1,2,3,3,3-pentafluoropropoxy)-2,4,5-trifluorobenzoic acid, 3-trifluoromethoxy-2,4,5-trifluorobenzoic acid, 3-chlorodifluoromethoxy-2,4,5-trifluorobenzoic acid, 3-(2,2,2-trifluoroethoxy)-2,4,5-trifluorobenzoic acid, 3-(2,2-dibromo-1,1-difluoroethoxy)-2,4,5-trifluorobenzoic acid, 3-(2,2-dibromo-1,1-difluoroethoxy)-2,4,5-trifluorobenzoic acid, 3- ( 1 ,2-dichloro- 1 ,2-difluoroethoxy)-2,4,5-trifluorobenzoic acid, 3-(2-chloro-1,1-difluoroethoxy)-2,4,5-trifluorobenzoic acid, 3-(2,2,3,3,3-pentafluoropropoxy)-2,4,5-trifluorobenzoic acid, 3-heptafluoropropoxy-2,4,5-trifluorobenzoic acid, 3-(2,2,3,3,4,4,4-heptafluorobutoxy)-2,4,5-trifluorobenzoic acid, 3-nonafluorobutoxy-2,4,5-trifluorobenzoic acid or 3-allyloxy-2,4,5-trifluorobenzoic acid.

These compounds can be obtained from 3-hydroxy-2,4,5-3-trifluorobenzoic acid by etherification of the hydroxy group. The reaction conditions correspond to those used in the preparation of the compounds of formulae Ib and Ilb from the compounds of formulae Ia and Ila.

The invention yet further relates to a process for the preparation of a compound of formula (1), which comprises converting a compound of formula (III) by nitration into a compound of formula (II), and decarboxylating said compound of formula (II), without working up, in a one pot synthesis.

A preferred process comprises carrying out the nitration in water in the temperature range from 10 to 50C with nitric acid, and the subsequent decarboxylation in the temperature range from 80 to 140C, if desired after partial removal and/or addition of a high-boiling wa~er-miscible solvent and in the presence of a base.

Example 1: 4-HvdroxY-2,3LS-trifluorobenzene H~

F ~ NO2 al) 2-Nitro-5-hYdroxv-3.4~6-trifluorobenzoic acid 1.3 ml of nitric acid (65 %) are added dropwise at 22C to a suspension of 3 g of 3-hydroxy-2,4,5-trifluorobenzoic acid in 35 ml of chloroform. The mixture is stirred for 4 hours and then poured into 200 ml of a saturated solution of sodium chloride. After extraction with 3xlO0 ml of diethyl ether, the combined ethereal phases are washed with 3xS0 ml of a saturated solution of sodium chloride, dried over magnesium sulfate and concentrated on a rotary evaporator. The crude product is stirred in carbon tetrachloride to give 3.4 g of pale yellow crystals. Recrystallisation from toluene gives the pure title compound with a melting point of 158-160C.

a2) 57.6 g of 3-hydroxy-2,4,5-trifluorbenzoic acid in 25 ml of water are added to 30 ml of nitric acid (65%). The mixture is stirred for 30 minutes, then poured on to 1000 ml of ice-water and solid sodium hydrogencarbonate is added until the neutral point is reached.
The pH is then adjusted to 1 with 37 ~o hydrochloric acid. After extraction with 3x250 ml of diethyl ether, the ethereal phases are combined, dried over magnesium sulfate, and the solvent is removed by evaporation. Recrystallisation from toluene gives pure 2-nitro-S-hydroxy-3,4,6-trifluorobenzoic acid with a melting point of 160-162C.

b) 4 ml of triethylamine are added dropwise at 110C to a solution of 2,65 g of 2-nitro-5-hydroxy-3,4,6-trifluorbenzoic acid in 20 ml of dimethyl sulfoxide and the mixture is stirred for another 2 hours. The reaction solution is then poured into 200 ml of water and the pH is adjusted to 3 with 37 % hydrochloric acid. After extraction with 3xlO0 ml of diethyl ether, the combined ethereal phases are washed with 3xS0 ml of a saturated solution of sodium chloride, dried over magnesium sulfate, and concentrated on a rotary evaporator to give the title compound with a melting point of 106- 108C.

Claims (18)

1. A process for the preparation of a compound of formula (I), wherein R is hydrogen, C1-C8alkyl, halo-C1-C8alkyl or allyl, which comprises decarboxylating a compound of formula II

(II), wherein R is hydrogen, C1-C8alkyl, halo-C1-C8alkyl or allyl, or a salt thereof.
2. A process according to claim 1, wherein the decarboxylation is carried out in the presence of a base.
3. A process according to claim 1, wherein the decarboxylation is carried out in an organic solvent, a mixture of an organic solvent and water or in water.
4. A process according to claim 1, wherein the decarboxylation is carried out in the temperature range from +50°C to +250°C.
5. A process according to claim 1, wherein the decarboxylation is carried out in the presence of a base; in an organic solvent, in a mixture of an organic solvent and water or in water; and in the temperature range from +50°C to +250°C
6. A process according to claim 1, wherein the decarboxylation is carried out in dimethyl sulfoxide, in the presence of triethylamine and in the temperature range from +80°C to +140°C.
7. A compound of formula II

wherein R is hydrogen, C1-C8alkyl, halo-C2-C8alkyl or allyl, or a salt thereof.
8. A compound of formula II according to claim 7, selected from the group consisting of 5-methoxy-2-nitro-3,4,6-trifluorobenzoic acid, 5-ethoxy-2-nitro-3,4,6-trifluorobenzoic acid, 5-propoxy-2-nitro-3,4,6-trifluorobenzoic acid, 5-isopropoxy-2-nitro-3,4,6-trifluorobenzoic acid, 5-butoxy-2-nitro-3,4,6-trifluorobenzoic acid, 5-tert-butoxy-2-nitro-3,4,6-trifluorobenzoic acid, 5-(1,1,1,2,3,3,3-hexafluoropropoxy)-2-nitro-3,4,6-trifluorobenzoic acid, 5-(1,1,2,2-tetrafluoroethoxy)-2-nitro-3,4,6-trifluorobenzoic acid, 5-(2-chloro-1,1,2-trifluoroethoxy)-2-nitro-3,4,6-trifluorobenzoic acid, 5-heptafluoropropoxy-2-nitro-3,4,6-trifluorobenzoic acid, 5-(1,2,3,3,3-pentafluoropropoxy)-2-nitro-3,4,6-trifluorobenzoic acid, 5-(2,2,2-trifluoroethoxy)-2-nitro-3,4,6-trifluorobenzoic acid, 5-(2,2-dibromo-1,1-difluoroethoxy)-2-nitro-3,4,6-trifluorobenzoic acid, 5-(1,2-dichloro-1,2-difluoroethoxy)-2-nitro-3,4,6-trifluorobenzoic acid, 5-(2-chloro-1,1-difluoroethoxy)-2-nitro-3,4,6-trifluorobenzoic acid, 5-(2,2,3,3,3-pentafluoropropoxy)-2-nitro-3,4,6-trifluorobenzoic acid, 5-(2,2,3,3,4,4,4-heptafluorobutoxy)-2-nitro-3,4,6-trifluorobenzoic acid, 5-nonafluorobutoxy-2-nitro-3,4,6-trifluorobenzoic acid, and 5-allyloxy-2-nitro-3,4,6-trifluorobenzoic acid, or a salt thereof.
9. 2-Nitro-5-hydroxy-3,4,6-trifluorobenzoic acid, or a salt thereof.
10. A process for the preparation of a compound of formula (II), wherein R is hydrogen, C1-C8alkyl, halo-C1-C8alkyl or allyl, which comprises reacting a compound of formula (III), wherein R is hydrogen, C1-C8alkyl, halo-C2-C8alkyl or allyl, with a nitrating agent.
11. A process according to claim 10, wherein nitrating acid is used as nitrating agent.
12. A process according to claim 10, wherein nitric acid is used as nitrating agent.
13. A process according to claim 10, wherein the nitration is carried out in the temperature range from 0°C to +60°C.
14. A process according to claim 10, wherein the nitration is carried out with nitric acid, in the presence of a solvent and in the temperature range from 0°C to +60°C.
15. A process according to claim 10, wherein the nitration is carried out with nitric acid, in chloroform and in the temperature range from +10°C to +50°C.
16. A process for the preparation of a compound of formula (I), wherein R is hydrogen, C1-C8alkyl, halo-C1-C8alkyl or allyl, which comprises converting a compound of formula (III), wherein R is hydrogen, C1-C8alkyl, halo-C1-C8alkyl or allyl, by nitration into a compound of formula (II), wherein R is hydrogen, C1-C8alkyl, halo-C1-C8alkyl or allyl, and decarboxylating said compound of formula (II), without working up, in a one pot synthesis.
17. A compound of formula (I), wherein R is halo-C1-C8alkyl or allyl.
18. A compound of formula I according to claim 17, selected from the group consisting of 4-(1,1,2,3,3,3-hexafluoropropoxy)-2,3,5-trifluoronitrobenzene, 4-(1,1,2,2-tetrafluoroethoxy)-2,3,5-trifluoronitrobenzene, 4-(2-chloro-1,1,2-trifluoroethoxy)-2,3,5-trifluoronitrobenzene, 4-(1,2,3,3,3,-pentafluoropropoxy)-2,3,5-trifluoronitrobenzene, 4-heptafluoropropoxy-2,3,5-trifluoronitrobenzene, 4-(2,2,2-trifluoroethoxy)-2,3,5-trifluoronitrobenzene, 4-(2,2-dibromo-1,1-difluoroethoxy)-2,3,5-trifluoronitrobenzene, 4-(1,2-dichloro-1,2-difluoroethoxy-2,3,5-trifluoronitrobenzene, 4-(2-chloro-1,1-difluoroethoxy)-2,3,5-trifluoronitrobenzene, 4-(2,2,3,3,3-pentafluoropropoxy)-2,3,5-trifluoronitrobenzene, 4-(2,2,3,3,4,4,4-heptafluorobutoxy)-2,3,5-trifluoronitrobenzene,, 4-nonafluorobutoxy-2,3,5-trifluoronitrobenzene, 4-trifluoromethoxy-2,3,5-trifluoronitrobenzene, and 4-chlorodifluoromethoxy-2,3,5-trifluoronitrobenzene.

FD4.5/FF/md
CA002084587A 1991-12-06 1992-12-04 Process for the preparation of trifluorobenzene derivatives Abandoned CA2084587A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
CH3594/91-7 1991-12-06
CH359491 1991-12-06
CN93100780A CN1090265A (en) 1991-12-06 1993-01-21 The method for preparing trifluorobenzene derivatives

Publications (1)

Publication Number Publication Date
CA2084587A1 true CA2084587A1 (en) 1993-06-07

Family

ID=48779259

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002084587A Abandoned CA2084587A1 (en) 1991-12-06 1992-12-04 Process for the preparation of trifluorobenzene derivatives

Country Status (10)

Country Link
EP (1) EP0545866A1 (en)
JP (1) JPH05246956A (en)
CN (1) CN1090265A (en)
AU (1) AU2989592A (en)
BR (1) BR9204847A (en)
CA (1) CA2084587A1 (en)
IL (1) IL103922A0 (en)
MX (1) MX9206997A (en)
NZ (1) NZ245362A (en)
ZA (1) ZA929419B (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10016723A1 (en) * 2000-04-04 2001-10-11 Bayer Ag Process for the preparation of dialkoxythiophenes and alkylenedioxythiophenes
GB0523853D0 (en) * 2005-11-24 2006-01-04 3M Innovative Properties Co Fluorinated surfactants for use in making a fluoropolymer
CN109467509B (en) * 2017-09-08 2021-09-24 联化科技股份有限公司 Preparation method of substituted nitrobenzene compounds

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4831190A (en) * 1986-12-04 1989-05-16 Ube Industries, Ltd. Trifluorohydroxyaromatic acid and preparation thereof
DE58904296D1 (en) * 1988-02-04 1993-06-17 Ciba Geigy Ag N-BENZOYL-N'-TRIFLUORPHENYL UREA MATERIALS, THEIR PRODUCTION AND USE IN THE CONTROL OF Pests.
FI95130C (en) * 1988-07-20 1995-12-27 Sankyo Co Process for the preparation of 4-oxoquinoline-3-carboxylic acid derivatives useful as a medicament

Also Published As

Publication number Publication date
EP0545866A1 (en) 1993-06-09
AU2989592A (en) 1993-06-10
IL103922A0 (en) 1993-04-04
MX9206997A (en) 1993-06-01
NZ245362A (en) 1993-11-25
CN1090265A (en) 1994-08-03
JPH05246956A (en) 1993-09-24
ZA929419B (en) 1993-06-07
BR9204847A (en) 1993-06-08

Similar Documents

Publication Publication Date Title
US4684734A (en) Method for manufacture or organic fluorine compounds
EP3812366A1 (en) A preparation method for m-diamide compounds
Finger et al. Aromatic Fluorine Compounds. II. 1, 2, 4, 5-Tetrafluorobenzene and Related Compounds1, 2
CA2084587A1 (en) Process for the preparation of trifluorobenzene derivatives
JPS63119434A (en) 3-bromo-4-fluoro-benzaldehyde acetal and manufacture
US4157344A (en) Preparation of aryl trifluoromethyl ethers
US4470930A (en) Preparation of nuclear chlorinated aromatic compounds
US4469893A (en) Method for the preparation of nitrodiphenyl ethers
US4051168A (en) Fluorination process
US3019268A (en) Nitrobenzylthioethanol compounds
CA1104589A (en) Alcohols
IE43614B1 (en) Diphenylamines
CN114436980A (en) Fluorinated geminal dinitromethyl substituted triazoles and pyrazoles and preparation method and application
Simonnin et al. A Nuclear Magnetic Resonance Study of some 4-X-Substituted-2, 6-Dinitroanisoles and Related Meisenheimer 1, 3-and 1, 1-Complexes
US3417153A (en) Polynitrobenzofluorides and the method of preparation thereof
US5142092A (en) Fluorine-containing acetophenones optionally halogenated on the CH3 -group and their precurser fluorine-containing benzonitriles
US3812194A (en) Novel process for preparing 6-halo-3-methylphenols
US4772730A (en) Tetrafluoro-2,3-dihydrobenzofurans
JPH0229667B2 (en)
US3574758A (en) Polynitrobenzophenone
KR800001276B1 (en) Method for preparing 4-nitro-2-trifluoromethyl diphenylamine derivative
US4346244A (en) Preparation of chloroalkoxybenzenes
CA1190241A (en) Phenylacetate as pest control agents
Panchatsharam et al. Chlorination of ketones with N-chlorosaccharin
JP2770895B2 (en) 4,5-dihalogeno-6- (α-halogenoethyl) pyrimidine and process for producing the same

Legal Events

Date Code Title Description
FZDE Discontinued