2-Benzimidazolecarbamic acid esters by the cyanamide process
申请人:E. I. Du Pont de Nemours and Company
公开号:US03997553A1
公开(公告)日:1976-12-14
A process for making 2-benzimidazolecarbamic acid, alkyl esters by reacting cyanamide or a cyanamide salt with an alkyl chloroformate in a weakly acidic to basic medium at a temperature between 0.degree. and 105.degree. C. to form an alkyl cyanocarbamate salt; then reacting the alkyl cyanocarbamate salt with an o-phenylenediamine in an acidic medium at a temperature between 40.degree. and 130.degree. C. to form the desired product and recovering it from the reaction mixture. The 2-benzimidazolecarbamic acid, alkyl esters are useful as fungicides and also useful as intermediates in the preparation of dialkyl esters of 2-carboxyaminobenzimidazole-1-carboxylic acids.