IL34611A - Process for the preparation of benzimidazole-2-carbamic acid esters - Google Patents

Description

Process for the preparation of acid esters Bayer the general formula at to in the presence of a It is surprisin in this reactions particularly an aminolysis of the ester do not occur no appear to be It is known that acid esters are aminolysed by amines Volume VIII The process according to the invention exhibits a series of The acid esters are obtained in high purity and excellent yield without an excess of one the other reactant being higher supply of energy is since the reaction already proceeds rapidly at If and methoxycarbonylisocyanide dichloride are used as starting the reaction course can be represented by the following formula X stands preferably for alkyl with carbon atoms such as methyl and with 1 or 2 carbon atone as As examples of compounds of formula there may be The are stands preferably for alkyl with carbon atoms phenylalkyl wit carbon atoms in the alky1 radical as benzyl and As examples of the compounds of formula there may be acid methyl isopropyl ester and The acid esters are not yet They be prepared in simple by reaction of the known dichloromethylenecarbamic chloride with alcohols or phenols in the presence of an inert organic such as at temperatures from 0 to As an the preparation of dichloromethylenecarbamic acid ethyl ester may be carried out To a solution of 300 g dichloromethylenecarbamic chloride in ml ether over there are added a of about with good cooling and g ethanol temperature between 15 and The solution is kept at room temperature for 2 the ether is distilled off and the product is The main fraction of 267 g of the mm is again distilled over a g of the 20 mm The main reaction of the invention may be carried out in the presence of a solvent term includes a mere All inert organic solvents are These include such as benzine or chlorinated such as such as diethyl ether or water or aqueous mixtures with organic as acetone or can also be The reaction according to the invention is carried out in the presence of a Suitable compounds include alkali metal hydroxides and alkaline earth metal carbonates and hydrogen tertiary organic As there may be sodium potassium potassium hydrogen triethylamine and The reaction temperatures can be varied within a fairly wide In the reaction is carried out at to preferably 0 to When carrying out the process according to the 1 mole of the may be in the presence of approximately 2 moles of the approximately 1 mole isocyanide Those carbamic acid esters of formula which are new can be used in the same manner as those which are already Thus there can be used fungicidal compositions containing as active ingredient a compound made by the process according to the invention in admixture with a solid diluent or carrier or in admixture with a liquid diluent or carrier containing a the compositions from to by weight of the The invention is illustrated by the following Example 1 To a mixture of g g trieth lamine and 300 ml chloroform there is added with a solution earbamie aeid methylester in 50ml temperature being kept to about by ice After 10 minutes of further suction filtration is effected and the precipitate is washed with After 19 g of the ester are The product decomposes somewhat at but remains Example 2 g together with 8 g sodium hydroxide are dissolved in a mixture of 200 ml water and 50 ml To the which is cooled to there are added dropwise g earbamie aeid ester in admixture wi h below by After 10 suction filtration is the precipitate is washed with water and acetone and 20 g melting Example 3 In analogous manner to that of Example 2 there are acid then becomes solid acid acid benzyl 2 then becomes solid Example 4 4g together with 8g sodium hydroxide are dissolved in a mixture 200 and 50 ml To the which is cooled to there are added dropwise earbamic aoia me in admixture with 50 ml the temperature being kept below by After 10 suction filtration is the precipitate is washed with water and acetone and 23 which may be purified from melting insufficientOCRQuality

Claims (1)

1. 34611/2 of the o-phenylenedianiine is reacted, in the presence of approximately 2 moles of the base, with approximately 1 mole of the isocyanide dichloride. 6, A process for the production of a compound of the formula (I), substantially as hereinbefore described in any of Examples 1-3» 7.. Compounds of the formula (I) whenever prepared by a process according to an of claims 1-6.* ND/ru