CS257534B1 - Method of cyclopropane acids' alpha-cyanobenzylesters preparation - Google Patents

Abstract

Process for the preparation of alpha-cyanobenzyl esters of formula (I) wherein R is 2,2,2-trihalothenethyl or a 2,2-dihalovinyl radical and R 4 and R 2 represent hydrogen or halogen, is that it is cyclobutanone of formula IV wherein X a Y represents a halogen atom; -5 to 100 ° C in an aqueous solution containing at least one molar equivalent of the first or second metal hydroxide; of the second group of the Periodic Table of the Elements, optionally an organic solvent is added to the resulting mixture is treated with at least one molar equivalent alkali cyanide and at least one molar an alkali carbonate equivalent and at least one molar equivalent of the sulfonic acid salt of formula (II) or a sulfonic acid salt of formula (III) or mixtures thereof; R 1 and R 2 are hydrogen or halogen and M + is an alkaline cation and at least one molar equivalent sulfonyl chloride of formula V π AND A-SO2C1 (V) wherein A is alkyl or aryl, optionally substituted, in an inert organic solvent, optionally in the presence of a phase transfer catalyst.

Description

The invention relates to a process for the preparation of cyclopropanoic acid alpha-cyanobenzyl esters represented by the general formula I, wherein R is a 2,2,2-trihalogenethyl or a 2,2-dihalo-vinyl residue 12 and R and R are hydrogen or halogen.

It is known that esters of this group exhibit insecticidal activity. It is known in the art that the alpha-cyanobenzyl esters of the formula I can be prepared by reacting cyclopropanoic acid chlorides with the alkali sulfonic acid salts of the formulas II or III or a mixture of these salts in the presence of alkali cyanides.

The disadvantage of this process is the limited availability and low stability of the cyclopropanoic acid starting chlorides.

The above-mentioned disadvantages are overcome by the process for the preparation of the alpha-cyanobenzyl esters of the formula I as defined above, which comprises dissolving the cyclobutanone of the formula IV in which X and Y are halogen at -5 to 100 ° C in aqueous a solution comprising at least one molar equivalent of the metal hydroxide of the first or second group of the Periodic Table, optionally in the presence of an inert organic solvent, and the resulting mixture is reacted in the presence of at least one molar equivalent of alkali cyanide, at least one molar equivalent of alkali carbonate; acids of formula II or III or mixtures thereof wherein and in each case have the meaning given above and represent an alkali cation, of at least one molar equivalent of the sulfonyl chloride of the general formula V

A-SO ₂ Cl, (V) wherein A is alkyl or aryl, optionally substituted in an inert organic solvent, optionally in the presence of a phase transfer catalyst.

An advantage of the invention is that it is possible to influence the configuration of the ester of formula I by selecting the reaction conditions of the reaction medium and the temperature. For example, if the cis-cyclobutanone (IV) is dissolved at low temperature in an aqueous solution of an alkaline hydroxide in the absence of an organic, water-miscible solvent, the present invention yields an ester of formula (I) with a predominant cis configuration on the cyclopropane core. By dissolving at a higher temperature and in particular in the presence of an organic water-miscible solvent, a considerable proportion of the trans-configuration ester of the general formula I is obtained on the cyclopropane core.

The optically active cyclobutanones of the general formula can be converted by the process according to the invention. IV directly to the optically active alpha-cyanobenzyl esters of formula I, with the predominant configuration of 1R-cis, or with the predominant configuration of 1S-cis on the cyclopropane ring, depending on the configuration of the starting cyclobutanone. This aspect of the invention is extremely important for the preparation of highly effective insecticidal compositions. The optically active cyclobutanones of formula IV are known and readily available.

Another advantage is the possibility of influencing the structure of the substituent R in the ester of the formula I by selecting the reaction conditions. For example, if the cyclobutanone of formula IV, where X = Y = C1, is dissolved in aqueous sodium hydroxide at -5 ° C and reacted with the other ingredients of the invention at room temperature, only the ester of formula I wherein R is 2.2 , 2-trichloroethyl. However, if the dissolution of the cyclobutanone of formula IV, where X and Y are as defined above, in aqueous sodium hydroxide by successive heating up to a temperature of 97 ° C, the ester of the general formula I is obtained as the main product, wherein R is 2,2-dichlorvinyl .

The actual reaction is simple. In one preferred method of the invention, after dissolving the cyclobutanone in an aqueous solution of sodium hydroxide and sodium carbonate, an inert water-immiscible solvent is added and the remaining reaction components are gradually added under vigorous stirring at 27 ° C. In this embodiment, it is preferable to operate in the presence of a phase transfer catalyst selected from the group of generally known catalysts of this type. For example, the reaction may be carried out in the presence of benzyltriethylammonium chloride, tetra-n-butylammonium halide. The sulfonyl chloride (V) used is, for example, methane sulfonyl chloride or p-toluenesulfonyl chloride.

The process of the invention is further illustrated by the following non-limiting examples.

Example 1

Ester I (R = CC1 ₃ -CH ₂ -, R ¹ = R ² = H)

1.32 g of cyclobutanone of formula IV, where X = Y = C1 (5 mmol), 1.2 g of sodium hydroxide (30 mmol) and 20 ml of water are stirred vigorously for 8 hours at -10 ° C and then added to the reaction mixture. carbonated, at room temperature and under stirring, add 10 ml of toluene, 0.67 g (3 mmol) of benzyltriethylammonium chloride, 1.9 g (10 mmol) of p-toluenesulfonyl chloride, 0.98 g (15 mmol) of potassium cyanide and 1, 55 g (5 mmol) of the sodium sulphonic acid salt of general formula II, where R = R = H. After 10 hours, the aqueous layer is separated, the organic layer is shaken with 2x20 ml of water and dried by evaporating toluene. The residue is an ester of formula (I) wherein R, R and R are as defined above, 1.85 g (82%), the purity of which is min. 94% (by gas chromatography).

For ^c 22 ^H 20 ^C1 3 ^NO 3 (452.8)

Calculated: C 58.36% C 4.45% H 24.49% Cl

Found: 58.22% C 4.35% H 24.6 i Cl

Example 2

Ester CLR I-cis, R-alpha, s] (R = CC1 ₂ = CH-, R ¹ = R ² = H)

The procedure of Example 1 was followed with the following variations. An optically active cyclobutanone of formula IV (where X = Y = Cl, [.alpha.] @ 33 ⁼ (CCl @ 4, c = 0.848), m.p.

50.5-51 ° C) and dissolution was first performed at -10 ° C for 8 hours and then at 100 ° C for 10 hours. According to the procedure of Example 1, an ester of formula (I) wherein R, R ⁴ and R ² are as defined above was obtained in a yield of 90% (1.88 g), which was min. 95% and tea ² ° = 16.5 °.

For ^C 22 ^H 19 ^C1 2 ^NO 3 (416.3)

Calculated: C, 63.47; H, 4.60;

Found: 63.58% C 4.68% H 17.2% Cl

Example 3

Esther I (R = CBr ₃ CH ₂ , R ¹ = R ² = H)

The reaction was carried out as in Example 1, using 1.99 g (5 mmol) of cyclobutanone of formula IV (X = Cl, Y = Br). The ester obtained above was isolated in a yield of 85% (1.64 g) and a purity of min. 92 $.

For C ₂₂ H _{2 ()} Br ₃ NO ₃ (586.1)

Calculated: C 45.08% H 3.44% 40.90 Br

Found: 45.17% C 3.56% H 41.4% Br

Example 4

Ester I (R = CC1 ₂ = CH-, R ¹ = p-chloro, R ² = H)

Example 1 was treated with these differences. 1.7 g (5 mmol) was used in the reaction.

2 mixtures of sodium salts of the formulas II and III, where R = p-chloro, R = H) and the dissolution of cyclobutyl 257534 nono were first carried out for 8 hours at -5 ° C, then for 10 hours at 90 ° i (82 *) ester I ( see above) purity min.91%.

1.84 g were isolated

For ^C 22 ^H 18 ^Cl 3 ^NO 3 (450.8) Calculated: 58.62% C 4.02% H Found: 58.51% C 3.90% H

Claims (4)

P 6 'E D M Ě T VYNALEZU A process for the preparation of alpha-cyanobenzyl esters of general formula I, wherein R is a 2,2,2-trihalogenethyl or 2,2-dihalo-vinyl radical and R and R are hydrogen or halogen, characterized in that cyclobutanone of the general formula IV wherein X is X and Y represents a halogen atom, dissolved at -5 to 100 ° C in an aqueous solution containing at least one molar equivalent of the metal hydroxide of the first or second group of the Periodic Table, optionally adding an organic solvent and treating the resulting mixture with at least one molar equivalent of alkali cyanide and at least one molar equivalent of an alkali carbonate and at least one molar equivalent of a sulfonic acid salt of formula II or a sulfonic acid salt of formula III or a mixture thereof, wherein R and R are hydrogen or halogen and M ⁺ is an alkali cation and at least one molar equivalent sulfonyl chloride of formula V a-so ₂ ci (V) wherein A is alkyl or aryl, optionally substituted, in an inert organic solvent, optionally in the presence of a phase transfer catalyst. 2. A process according to claim 1, wherein cyclobutanone IV is used, wherein X and Y are the same and are chlorine. 3. The process of claim 1, wherein the cyclobutanone of formula IV is used wherein X is chlorine and Y is bromine. 4. The process according to claim 1, wherein the cyclobutanone IV used is optically active 1 drawing