CS270010B1 - Process for the Preparation of Optical IaAARA cla--2,2-diaethyl-3- (2'-2-dihalomethyl) cyclopropanecarboxylic acid - Google Patents

Abstract

A method for preparing organic cis-2,2-diethyl-3-/2,2-dihalovinyl/cyclopropanecarboxylic acids of the general formula I, where X is halogen, consists in reacting a stereoisomeric acid of the general formula I, where X is halogen of the absolute configuration of Rcis and Rcis, with an aromatic compound of the general formula II, where Y represents a group -CH-CH-, oxygen, nitrogen or -NH- and Z represents hydrogen, methyl or halogen, at -50 to 100 °C, optionally in an inert organic solvent, whereby a crystalline addition compound of the general formula III, /Rcia-X/ . /Scia-I/ . /11/ /111/ consisting of 1 equivalent of the stereoisomeric acid of the general formula I, is precipitated from the reaction mixture; where X has the above meaning, the absolute configuration of 1 Rcio (lRci5-I), 1 equivalent of the aromatic compound of the general formula I, where X has the above meaning; in the absolute configuration of 1 Scla (lSola-Z) and 1 equivalent of the aromatic compound of the general formula II; where Y and Z have the above meaning, in an equimolar ratio, while the predominant stereoisomer of the acid of the general formula I, where X has the above meaning, is dissolved, chemically unchanged. The preparation method is advantageously used in the synthesis of various pyrethroid insecticides

Description

The present invention relates to a process for the preparation of optical leomers of 2,2-dimethyl-3- (2,2'-2-dihalovinyl) -cyclopropanecarboxylic acids of the general formula I, in which X represents a halogen atom, it being known that certain esters The acids of formula I are active ingredients in a number of insecticidal agents (e.g. permethrin / cypormethrin / alfenethrin, doltemethrin). It is also known; that the individual stereoioners of these esters have insecticidal activity, whereas the esters containing the acid of formula X with the absolute configuration IRcis show much higher activity than the corresponding stereoisomers with the configuration of the acid component ISciS.

Furthermore, various methods for the preparation of the individual etheroisoners of the acid of the formula I are known (see, for example, diootoreoionic derivatives.

Nedoetatken processes based on aneynetrical synthesis is a technical complexity accompanied by a poorly satisfactory stereoolactivity, as a result of which uniform etheromers are not formed; but only optically more or sledges enriched in etorooomorphic mixtures; which must be subsequently separated * The proton uses similar procedures as the ionic form of the obsonic acid of the formula I, i.e. * separation of diastereoisone derivatives / more often fractional crystallization of salts with optically active base *.

Due to the technically satisfactory efficiency of the processes based on the separation of diasteroolomers, the particularly satisfactory efficiency and, in particular, the difficulty of processing the diaphoromeric components remaining during crystallization in inert liquors *,

Said drawbacks of speech are the method according to the invention; the essence of which consists in the action of etorooomorphic kyeolins of general formula 1 / wherein X jo halogen * abeolute configuration of IRcie o IScie eo acts with an ammononic compound of general formula XX; wherein Y is -CH-CH- (oxygen) sulfur nsbo -NH- and Z is hydrogen * ¹ methyl or halogen, at -50 to 100 ° C optionally in an inert organic solvent *, whereby a crystalline starting material of general formula is precipitated from the reaction mixture. formula XXX (IRcie-I). / IScie-I /. / IX / (xxx) comprising duty etereoisomory acid obočného, I * one X is as above defined * abeolutní configuration IRCI / LRCI-L) * "duty eterooioomor kyeoliny formula X * start X has front uvedoný meaning ¹ in absolute konfigursci IScis (1Scis) and an aromatic compound of formula II; who Y and Z have the meanings given above, in equimolar ratio, while the predominant oterooieomor cle kyeolines of general formula X; wherein X is as defined above; it remains chemically unchanged in the reaction mixture. containing both optical antipodes IRcls-I and IScie-Ι in an equimolar ratio (1 s 1), regardless of the representation of both etoroolooaors in the starting emolea. Izo is advantageously used for this preparation for the preparation of optical leomers from atoreoisooric acid mixtures of the general formula I (where X is as defined above) containing unequal proportions of IRcis-I and IScis-I leomers.

In the preparation process according to the invention, the non-equimolar emulsions of the stereoisomers IRcis-I and 1 Scie-I are treated with a compound of the formula II; kds Y and Z are as defined above; in an inert organic solvent or preferably without a solvent; optionally at elevated temperature, wherein part of the stereoisomers IRcls-I and iScia-I; which is present in an equimolar ratio, eliminates, if appropriate, by cooling from solution or melt in the form of a cryetallic addition compound of the formula III / X and Y and Z in the general formulas I o II, the meaning given above and the meaning given above / while the predominant ethoxyomer IRcis-I or IScie-Ι remains unchanged and can be obtained from a crystalline adduct of formula III, wherein X; Y and Z in formulas I and II are as defined above; separate by known methods * eg filtration or centrifugation. Addition compound III / wherein X / Y and Z in formulas I and II have

CS 270 010 B1 as defined above, can be easily decomposed into starting components, e.g. heating * to 25 to 100 ° C; optionally under reduced pressure up to 150 Pa, to give the racemic acid form of formula I, wherein X is as defined above *.

Thus, this process * delays the racic and optically active acid forms of the formula I, and, in contrast to the processes used hitherto, the presence of a post-optically active optically active component is not required. This circumstance is one of the new aspects of the invention.

The preparation process according to the invention can be used if a non-equimolar mixture of storeoisomers IRcis-I and IScis-I is available or in combination with other processes for the preparation, separation or chemical transformation of stereoisomers of general acid I, where x is as defined above. The combination of the process according to the invention with the resolution of the racemic acid of the formula I is preferred; where X is as defined above, with optically active bases. '

The essence of the invention and methods of its use are further illustrated by the following examples, which, however, do not limit the scope of the invention in any way.

Example 1 Separation of the IRcis isoform of cis-por * ethrinic acid (IRcie-I »X« C1) from the reactive form of the acid (IRcie-I: X «C1) using the benzene editing compound * / II j Y» -CH »CH -, Z »H /

36.3 g of levorotatory cie-permethrinic acid,--9.8 (CHCl ₃ ) were dissolved in 44 ml of benzene at reflux and the solution was cooled in January with stirring. The precipitated adduct of formula III was filtered off with suction, quenched with benzene and quenched by heating in vacuo (80 DEG C., 24 hours) to give 21.6 g of the racemic acid of formula 1. From the combined mother liquors, 13% was obtained. 1 g of optically active acid of general formula I, □ ° - -27.22 ° (CHCl ₃ ).

Example 2

Separation of the Rcis isoer from the acid racemate of the general formula I / X * C1 / by means of an addition compound with thiophene / II> Y ”-S-, 'Ζ · Η /

The procedure was the same as in Example 1, except that 36 ml of thiophene were used for benzene. 24.4 g of a crystalline adduct of the general formula III were obtained, the thernic decomposition of which gave 20 g of the racemic kyeolin of the formula i; 0; 0 ° (CHCl ₃ ). Evaporation of the filtrates gave 14.6 g of optically active acid; -29; 17 ° (CHCl ₃ ).

Example 3 Cleavage of a racemic acid of the general formula I / X »C1 / using a benzene adduct

To a solution of 50 g of the racemic acid of the formula I in 800 * 1 of toluene at 60 DEG C. was added 18-85 g of n-methylbonzylamine in * 100 * 1 of toluene, and the solution was allowed to stand until the next day at room temperature. The precipitated crystals were removed with toluene. The crude salt was crystallized five times from toluene (25 * 1 toluene per 1 g of salt) to give 19.12 g of salt, mp 156-163 ° C, -34.66 ° (CH ₃ OH). The salt was partitioned between 200 ml

5% NaOH and 100 mL toluene. The toluene layer was separated and the aqueous shaken was washed once more with 100 ml of toluene. The aqueous portion was quenched with hydrochloric acid (pH 1-2) * shaken 3 times with 100 ml of ether. The ether extracts were combined, dried and the ether evaporated. It ziekáno 11, '82 g kyeeliny formula I, one X> C1 +34; 01 ° / CHC1 ₃ /. The combined mother liquors were evaporated; partitioned between 250 ml of a 5% solution of NoOH and 150 * 1 of toluene and treated as in the case of ehora ashed crystalline salt. Yield 36.3 g of the crude acid of Formula I, -9, 8 ° / CHC1 ₃ / which stalks befell worked-up as described in Example 1. * Total balance: at 56 '7% konverei zíekáno was 83% (♦) cyelines of formula I (opt. purity 95%) and 92.1% (-) acids of formula i; optical purity 77%.

Example 4 Cleavage of racemic kyeolin I / X <C1 / e using a thiophene adduct 25 g of the racemic acid of formula I were dissolved in 750 ml of toluene,

A solution of 1 g / - / - of sodium in 375 ml of toluene was added and, after inoculation, the solution was stirred for 7 hours from ice-cooling. according to Example 3, 6.67 g (♦) of acid, 3232, 67 ° (CHCl3) was treated. The mother liquors were treated according to Example 3 to give 18 g of crude (-) - acid, from which 18 ml of thiophone were treated according to Example 2; of formula I, 29.7 °.

The total balance at 59.3% conversion was 90% (β) -acid of formula I, optical purity 92% and 98% (-) - acid of formula I, optical purity 82%.

Claims (2)

OF THE INVENTION First pressurized feed vessels of Optical isoaerů ^cis-2, 2-dlnethyl «3/2 ^ 2-dihalovinyl / kyeeliny cyclopropanecarboxylate of formula I; who X is one hundred · halogen; characterized by ee tle; whereas the ether ethers of the general formula Xj wherein X is a halogen of the absolute configuration iRcie e IScle; eo is treated with an aromatic compound of formula XX, wherein Y is -CH>CH-; oxygen, sulfur or -NH- and Z are hydrogen, methyl or halogen, at -50 DEG to 100 DEG C., ee precipitating from the reaction phase a crystalline addition compound of formula XIX; / IRcie-I / · / IScie-I /. (11) (111) looking for ee from 1 equivalent of cle etoreoleoser of the acid of formula i; who X has the above meaning; abeolutnl configuration IRcio / 1Rcie-x; 1 equivalent to a stareoisolator of the acid of formula X; who X aé means the foregoing; in the absolute configuration IScle (IScie-I) and 1 equivalent of an aromatic compound of formula IX; wherein Y and Z are as defined above; while, in view of the ethoxyols of the formulas of the formula X, in which X and the abovementioned meanings, * remain dissolved, choically unchanged, and the crystalline addition compound of the formula III; who X; Y and Z in formulas I and II are as defined above; separated by decantation, filtration or separation * 2. A process for the preparation of a racemic acid of the general formula I, which X and the aforementioned meanings according to item 1, characterized in that the crystalline adduct of the general formula III, wherein x, Y and Z in the general formulas I and II have the meaning given above, decomposes heat treatment in the temperature range of 25 to 100 ° C; optionally at an anon pressure of up to 150 Pa.