FR2583045A1 - PROCESS FOR THE PREPARATION OF PYRETHROID DERIVATIVES - Google Patents

Abstract

THE PRESENT INVENTION CONCERNS A NEW PROCESS FOR THE PREPARATION OF PYRETHROID DERIVATIVES OF FORMULA I: (CF DRAWING IN BOPI) HAVING AN INSECTICIDE ACTIVITY. IN THE DESCRIPTION, THE SUBSTITUTES ALWAYS HAVE THE FOLLOWING DEFINITIONS: -R1 REPRESENTS A HALOGEN ATOM OR A METHYL; -R2 REPRESENTS A HYDROGEN OR A -CN GROUP; -R3 REPRESENTS A MONO- OR BICYCLIC GROUP SUBSTITUTELY SUBSTITUTED OR CONTAINED A C1 TO C4 ALCOYL; -R4 REPRESENTS A HYDROGEN ATOM OR A C1 TO C4 ALCOHYL; -R5 REPRESENTS A HYDROGEN ATOM OR A C1 TO C4 ALCOHYL; -R6 REPRESENTS A C1 TO C4 ALCOHYL SUBSTITUTE OR (CF DRAWING IN BOPI) OR R1 REPRESENTS A HALOGEN OR METHYL ATOM; -R7 REPRESENTS A HYDROGEN ATOM; -R6 AND R7 TAKEN TOGETHER REPRESENT AN ALCOTUELENE OR NOT SUBSTITUTE SUBSTITUTE FOR C1 TO C4; -R8 REPRESENTS AN AROMATIC OR HETEROAROMATIC GROUP WHICH IS POSSIBLE SUBSTITUTED.

Description

The present invention relates to a novel chemical process for

  preparation of pyrethroid derivatives of formula (1)

R5 R4

C R2

? - - R3

HC \ C - COO-- - R

R R

having an insecticidal activity.

  In the description, the substituents always have the defini-

  R1 represents a halogen atom or a methyl R2 represents a hydrogen or a group -CN R3 represents a substituted mono- or bicyclic group optionally containing a heteroatom or a C1-C4 alkyl; R4 represents a hydrogen atom or C1 to C4 alkyl R5 is hydrogen or C1 to C4 alkyl R6 is substituted C1 to C4 alkyl or R1 C = CH-R1 / o R1 is halogen or methyl, R7 represents a hydrogen atom, R6 and R7 taken together represent a substituted or unsubstituted C1 to C4 alkovene, R8 represents an aromatic or heteroaromatic group

optionally substituted.

  Those skilled in the art know several processes for the preparation of ester compounds of formula (I) having an insecticidal activity: According to the German patent application published under No. 2,947,127 and US Pat. No. 4,024,163, the appropriate alcohol is reacted. with the halide or anhydride derivative of the carboxylic acid of formula (II). German Patent No. 2,437,882 describes the reaction of the salts of compounds of formula (II) with m-phenoxybenzylhalides in a yield of 85-92%. European Patent No. 67,461 describes the esterification reaction by treating the carboxylic acid of formula (II) with the arylsulfonates of the alcohol components in a two-part system.

  phases using a phase transfer catalyst.

  In addition, trans-esterification processes are known in which the ethylcarboxylate of formula (II) is converted using m-phenoxybenzaldehyde-cyanhydride-acetate (US Pat.

No. 4,288,610).

  Using the methods mentioned above, the desired insecticides can generally be obtained in good yield, but undesirable side reactions often occur. So,

  for example, when using acid halides as acylating agents,

  lants - given their decomposition and the appearance of different

  impurities - side reactions often occur. Purification

  unstable and sensitive acid halides is very difficult.

  LEMENT. In addition, as in connection with the preparation of halides

  of acids, with the regeneration of tertiary bases used for acyl-

  subsequent protection and the protection of the environment, various difficulties may arise, the above processes can not be

  used on an industrial scale.

  When the acylation is carried out with acid anhydrides,

  only one of the acyl groups can be used because of the low reactivity

tivity of the compound.

  The arylsulfonate derivatives of the appropriate alcohols can be obtained.

  with a yield of not more than 90%, and in addition tosyl chloride

  commonly used is a fairly expensive reagent.

  In the case of a trans-esterification reaction, it is difficult to ensure a 100% conversion; moreover the target product

  is still contaminated with the starting materials.

  The invention relates to a continuous or batch process for the preparation of ester compounds of formula (I) by reacting a carboxylic acid salt of formula (II)

R5 R4

HC - C - COOH

R \ R7

  or the salt of the corresponding alkyl-carboxylate with a chloroformate of formula (III) Cl COO-CH-R 3 III 1 2 R preferably in the presence of a solvent and then release of carbon dioxide from the mixed anhydride of formula (IV)

R5 R4

/ \ / I

HO - C - C

R4 \ R7 \

R3 CH- 0 - C

12 O

  R 0 thus obtained preferably by basic treatment or acid and / or heat,

  optionally in the presence of a catalyst.

  The novel process of the invention is based on the recognition of

  This is because the mixed anhydrides of the carbonic acid esters of cyclopropane carboxylic acids, prepared for the first time by the Applicant, are unstable and can be transposed after loss of carbonic acid while the alcoholic esters are obtained.

  corresponding cyclopropane carboxylic acids.

  The starting carboxylic acids of formula (I) can form different isomers as it appears from their formula, so that they can be used for the purpose of the invention in the form of all cis and trans isomers as well as mixtures thereof, and further in the form of optically active isomers and racemates. The products are thus obtained in the form of the different isomers, in particular if R2 represents a -CN group. The invention includes all isomers

and their mixtures.

  The carboxylic acids of formula (II) or their esters can be reacted with the chloroformates of formula (III) in the form of their salts obtained with an alkaline hydroxide or with an organic base

  in an aqueous or organic solvent medium.

  The chloroformates of formula (III) are new and can be prepared by reacting the corresponding alcohol with phosgene in the presence of chlorobenzene or triethylamine as the acid binding agent. For example, the following chloroformates can be used preferably in the process according to the invention: Specific weight n Pf Peb

m-phenoxy-benzyl

  chloroformate 1.55 1.5845 120-130 / mm Hg

tetrahydro-phthalimido

methanol-chloroformate 28-30 C

m-phenoxy-benzaldehyde

cyanhydrine-

  The reaction of the salt of the carboxylic acid of formula (II) with the ester of formula (III) is preferably carried out in water and / or in an organic solvent. In an aqueous medium, it is generally reacted

  alkali salts, preferably the sodium, potassium or amine salts.

  monium. In this case it is desirable to also add a water-immiscible solvent having a low boiling point, which makes the isolation

easier.

  When the reaction is carried out in a dry solvent, it is preferred to use the carboxylic acid salts formed with tertiary amines. In the reaction mixture, the mixed anhydride of formula (IV) is provisionally formed from which, after removal of the carbon dioxide, the desired product is obtained. The preferred solvents for this reaction are the chlorinated hydrocarbons, and the removal of carbon dioxide, which if any already begins at the temperature

  ambient, can be accelerated or favored appropriately.

  To these effects it is possible to use different catalysts, e.g. ex. Lewis acids, strong mineral or organic acids, alkali hydroxides or organic bases. In the process of the invention, pyridine in an entirely small amount (trace) can be considered as a particularly preferred catalyst. In this case the reaction is already

completed at 50-60 C in 1 hour.

  The removal of carbon dioxide can be accelerated with heat treatment. In such cases the reaction is conducted

  at 0-150 C, preferably at 30-100 C.

  For the isolation of the product, known methods are employed.

  If anhydrous organic solvents are used, the precise salts are filtered off.

  The filtrate is concentrated to remove the solvent and thus the product can be obtained in a very pure quality. If a two-phase aqueous system is used, the phases must be separated and then the pyrethroid ester is obtained from the organic phase. If the product

  is used as an insecticidal active ingredient, no further purification

more is needed.

  According to the new process of the invention, the product is obtained with a high purity and with a good yield. It can not happen

  change in the ratio of isomers during the racemaking process.

  in the case where optically active starting materials have been used.

  The novel process is particularly suitable for the preparation of compounds of formula (V) belonging to the narrower framework of

compounds of formula (1).

  The ester compound of formula (V) can be prepared

RWCH 3 R2

1 C = CH-CH-CH-COO-C-R 8

  R 1, R 1 and R 2 are as mentioned for compounds of formula (I) and R 8 is an optionally substituted aromatic or heteroaromatic group. by reacting a salt of a carboxylic acid of formula (VI)

CH CH3

Rlu t C. 3

R C = CH-CH-H-COOH

  VI - o R1 is as mentioned above -with a chloroformate of formula (VII)

C1 - 00C0 - CH - R8

  R VII - R 2 and R 8 are as mentioned above - preferably in the presence of a solvent, then removing the carbon dioxide from the mixed anhydride of formula (VIII) thus obtained,

CH3 / CH

3 c Cnl., / \ .0

R1 C = CH-CH-CH-C

R -CH-O-C

> 2

R 0 VIII

  - o R1, R2 and R8 are as mentioned above - preferably using a basic or acidic and / or thermal treatment and the case

a catalyst is required.

  The process according to the invention can be advantageously used for the industrial scale preparation of known pyrethroid esters. It is particularly preferred to use, as starting materials, alkyl-2,2-dimethyl-3- (2,2-dimethylvinyl) -cyclopropane-carboxylate salts,

  alkyl-2,2-dimethyl-3- (2,2-dichloro-vinyl) -cyclopropane carboxylate or alkyl

  2,2-dimethyl-3- (2,2-dibromo-vinyl) -cyclopropane carboxylate or any of their isomers and tetrahydro-phthalimido-methyl-chloroformate,

  m-phenoxy-benzyl-chloroformate or m-phenoxy-benzaldehyde-cyanhydrin

  chloroformlate. The method of the invention is specified by the examples

following non-limiting

EXAMPLE 1

  209 g (1 mole) of (2,2-dichloroethenyl) -2,2-

  dimethyl-cyclopropanecarboxylic acid (cis / trans ratio: 40/60) in 1 liter of 1,2-dichloroethane, then a mixture of 140 ml (1 mole) of triethylamine and 10 ml (0.124 mole) of pyridine is added, followed by Charge 265 g (1 mole) of m-phenoxy-benzyl-chloroformate dropwise with stirring to the reaction mixture for 10-15 minutes. The salt precipitates immediately, the temperature rises to 28-31 C, while the cleavage of carbon dioxide also begins. After the end of the charge,

  the reaction mixture is heated to 55-60 ° C and stirred at this temperature.

  erased for 1 hour. During this period the elimination of the carbon dioxide is completed. After cooling, the reaction mixture is mixed with 1 liter of water, the organic phase is separated off, the aqueous phase is extracted with 200 ml of dichloroethane, the organic layers are combined and they are successively washed with 2 × 200 ml of aqueous solution. of sodium carbonate (5%) and 2 x 200 ml of hydrochloric acid solution

  (2%), dried over sodium sulphate and distilled to remove the dichloro-

  ethane. 376 g of (3-phenoxy-phenyl) -methyl-3- (2,2-dichlorophenyl)

  ethenyl) -2,2-dimethylcyclopropane carboxylate. Purity: 97%, yield:

2 93.3%. Cis / trans ratio: 40/60.

EXAMPLE 2

  209 g (1 mole) of (2,2-dichloroethenyl) -2,2-

  dimethyl-cycloperopane-carboxylic acid (cis / trans ratio 40/60) in a solution of sodium hydroxide (40 g / l) and introduced dropwise

  in the mixture for 10-15 minutes 10 ml of pyridine, 1 liter of di-

  chloroethane, 263 g (1 mole) of m-phenoxy-benzyl-chloroformate. The training

  Carbon dioxide immediately begins and the temperature rises to 30-35 C. After the end of the charge, the mixture is heated at 5560 C for 1 hour. After cooling, the phases are separated, the aqueous phase is extracted with 200 ml of dichloroethane,

  the organic layers, dried and distilled to remove the dichloro-

  ethane. 378 g of (3-phenoxy-phenyl) -methyl-3-2,2-dichlorobenzene are obtained.

  ethenyl) -2,2-dimethyl-cyclopropane-carboxylate. Purity: 98%. yield:

  94.7%. The cis / trans ratio remains unchanged.

  237 g (1 mol) of ethyl are stirred at 65 ° C. for 2 hours.

  (2,2-dichloroethenyl) -2,2-dimethyl-cyclopropane carboxylate (cis / trans ratio: 42/58) and 25 ml of 27% sodium hydroxide solution in the presence of

  low amount of a emuisifier. An additional amount is then added

  sodium hydroxide solution (25 ml) and the mixture is stirred for a further three hours. The solution is then poured into 500 ml of hot water, allowed to settle for 1 hour and the phases are separated. The lower organic layer is dried and filtered. The filtrate is 135 g (0.57 mol) of (2,2-dichloroethenyl) -2,2-dimethyl-cyclopropane carboxylate

  (cis / trans ratio: 55/45, "rich-isomer-cis" fraction).

  In the aqueous phase containing the sodium salt of (2,2-dichloroethenyl)

  2,2-dimethyl-cyclopropane (cis / trans ratio: 25/75) 4 ml of pyridine and 400 ml of dichloroethane are added and then 113 g (0.43 mol) of m-phenoxybenzylchloroformate are added dropwise. for 10-15 minutes while shaking. The process is then followed as described in the example

  2. 163 g of (3-phenoxy-phenyl) -methyl-3- (2,2-dichloroethenyl) -

  2,2-dimethyl-cyclopropane-carboxylate. Yield: 95.1%.

EXAMPLE 4

  Following the procedure described in Example 1 and using 168 g (1 mole) of chrysanthemic acid (cis / trans ratio: 20/80) and

  244 g (1 mole) of tetrahydro-phthalimido-methyl-chloroformate as

  starting materials and, instead of dichloroethane, dichloromethane as

  solvent, 320 g of 1,3,4,5,6,7-hexahydro-1,3-dioxo-2H-isoindole-

  2-methyl-2,2-dimethyl-3- (2-methyl-1-propenyl) -cyclopropanecarboxylate

  (cis / trans ratio: 20/80). Purity: 97%. Yield: 93.7%.

EXAMPLE 5

  Following the procedure as described above and using

  209 g (1 mole) of cis- (3-phenoxy-phenyl) -methyl-1- (2,2-dichloroethenyl) -

  2,2-dimethylcyclopropanecarboxylate and 287.5 g (1 mole) of m-phenoxy-

  benzaldehyde-cyanohydrin-chloroformate as starting materials,

  obtains 408 g of (RS) -alpha-cyano-3-phenoxy-phenyl- (1RS) -cis-3- (2,2-di-

  chloro-vinyl) -2,2-dimethyl-cyclopropane-carboxylate. Purity: 96%. yield:

94.1%.

EXAMPLE 6

  Following the procedure as described above and using

  298 g (1 mole) of decametric acid and 287.5 g (1 mole) of

  benzaldehyde-cyanohydrin-chloroformate, 486 g of (S) -alpha-

  cyano-3-phenoxy-benzyl- (1 RS) -cis-3- (2,2-dibromo-vinyl) -2,2-dimethylcyclohexyl-

  propane-carboxylate. Purity: 96%. Yield: 92.3%.

EXAMPLE 7

  116 g (1 mole) of cis / trans 2-hydroxy-methyl acid are mixed

  cyclopropanecarboxylic acid with 1 liter of 1,2-dichloroethane, 140 ml (1 mole) of triethylamine and 10 ml (0.124 mole) of pyridine and 109 g (96 ml, 1 mole) of ethyl chloroformate are added to the mixture.

  thus obtained in 10-15 minutes while stirring. At the same time as

  immediate piting of salt and raising the temperature to 58-62 C, the formation of carbon dioxide also begins. Stir the mixture

  for 1 hour but after 30 minutes the temperature drops

  the production of carbon dioxide becomes weaker and finally stops. At this time, the mixture is mixed with 1 liter of water, the organic phase is separated off and the aqueous phase is extracted with 2 × 200 ml of dichloroethane. The organic layers are combined, washed successively with 2 x 200 ml of 5% sodium carbonate solution and 2 x 200 ml of 2% hydrochloric acid solution, dried over sodium sulfate and distilled to remove dichloroethane. We

  141 g of cis / trans ethyl-2-hydroxy-methyl-cyclopropanecarboxylate are obtained.

Purity: 91.5%. Yield: 89.5%.

EXAMPLE 8

  Following the above procedure and using 140 g (1 mole) bicyclo / 4.1.0 / heptane-1-carboxylic acid and 109 g. (96 ml, 1 mole) of ethyl chloroformate as starting products, we obtain

  g of ethyl-bicyclo [4.1.0] heptane-1-carboxylate. Yield: 93.3%.

Claims (8)

  1. Process for the continuous or discontinuous preparation of ester compounds of formula (I) R5 R4 R2 C R / \ 1 3 C-c-coo-COO-R3 I R6 \ R7   R 2 represents a hydrogen or a group -CN R 3 represents a substituted mono- or cyclic group optionally containing a heteroatom or a C 1 -C 4 alkovyl; R 4 represents a hydrogen atom or a C 1 -C 4 alkyl; R 5 represents an atom of hydrogen or C1-C4 alkyl; R6 is C1-C4 substituted alkyl; or C = CH-R1; R1 is halogen or methyl, R7 is hydrogen, R6 and R7 are taken together; substituted or unsubstituted C1-C4 alkylene, in which one proceeds by reaction of a carboxylic acid salt of formula (IL) R5 R4   ## STR1 ## R4, R5, R6 and R7 are as mentioned above - or a salt of its alkyl ester with the chloroformate of formula (III) Ci-000-CH-R3 II R 2 and R 3 are as mentioned above - preferably in the presence of a solvent. then removing the carbon dioxide from the mixed anhydride of formula (IV) R5 p C / 3 o / S / Or o ' R3- CO - O- 0 2 o thus obtained,   R2, R3, R4, R5, R6 and R7 are as mentioned above - preferably   by using a basic or acidic and / or thermal treatment and the   optionally in the presence of a catalyst. 13 2583045   2. Process for the continuous or discontinuous preparation of the ester compounds of formula (V) CH CH3 2 R1 / C = CH-CH-CH-COO-CH-R   R1 represents a halogen atom or a methyl, R2 is as mentioned in claim 1, R8 represents an optionally aromatic or heteroaromatic group; substituted -   in which a salt of the carboxylic acid of formula (VI) is reacted CH C R1 'C H 3   R 1 is as defined above - or a salt of its alkovl ester with a chloroformate of formula (VII) ## STR5 ## 1 - COO-- -CH R8 VII   RC - o R2 and R8 are as mentioned above - preferably in the presence of a solvent, then the carbon dioxide is removed from the mixed anhydride of formula (VIII) CH3 / CH3 - C RA- / \! _ 0 R 1 C = CH-CH-CH-C R S-CH-O-C 2 2 R O   R 1, R 2 and R 8 are as mentioned above - preferably using a basic or acidic and / or thermal treatment and the case   optionally in the presence of a catalyst.   3. Process according to claim 1, wherein the salt of the carboxylic acid of formula (II) - R4, R5, R6 and R7 are as defined in claim 1, with an alkaline hydroxide or with an alkali metal hydroxide.   organic base, preferably in an aqueous or organic solvent medium.   4. Process according to claim 2, in which the salt of the carboxylic acid of formula (VI) - R 1 is as defined in claim 2 - or the salt of its alkyl ester with an alkaline hydroxide or with an organic base, preferably in an aqueous solvent medium or organic.   5. Process according to claim 1, in which the salt of the carboxylic acid of formula (II) - R4, R5, R6 and R7 are as defined in claim I1 - is reacted with the ester compound of formula ( III) - o R2 and R3 are as defined in claim 1 - in   an aqueous and / or organic solvent medium.   6. Process according to claim 2, wherein the salt of the carboxylic acid of formula (VI) - R 1 is as defined in claim 2 - or the salt of its alkyl ester with the ester compound is reacted.   of formula (VII) - o R2 and R8 are as mentioned in the claim   2 - in an aqueous and / or organic solvent medium.   The method of any one of claims 1-6, wherein   carbon dioxide, organic bases, strong inorganic or organic acids or   Lewis acids as catalyst and the decomposition of the   mixed hybrid at 0-150 C, preferably at 30-100 C.   The method of any one of claims 1-7, wherein   the alkyl-2,2-dimethyl-3- (2,2-dimethylvinyl) cyclopropane salt is used.   carboxylate, alcovl-2,2-dimethyl-3- (2,2-dichloro-vinyl) -cyclopropanecarbo-   xylate or alkyl-2,2-dimethyl-3- (2,2-dibromo-vinyl) cyclopropanecarboxylate or any of their isomers and m-phenoxy-benzylchloroformate,   tetrahydro-phthalimido-methyl-chloroformate or m-phenoxy-benzaldehyde   cyanohydrin-chloroformate as starting materials.