GB813771A - New di-imidazole derivatives and process for their manufacture - Google Patents

Abstract

The invention comprises compounds of the formula <FORM:0813771/IV (b)/1> where A is an aromatic nucleus (which may be substituted) attached by vincinal carbon atoms, and R and R1 are H or the same or different alkyl, hydroxyalkyl or benzyl groups. Preferably the groups R and R1 have 1 or 2 carbon atoms and A is unsubstituted, but the latter may have halogen, alkyl or alkoxy substituents. The invention also includes salts of the products, e.g. with sulphuric, hydrochloric, nitric, formic or acetic acid. The compounds are made by reacting, with or without a catalyst, the appropriate o-diamine with malic acid or a functional derivative thereof (e.g. lower alkyl ester). The reaction proceeds via the malic acid diarylide which may or may not be isolated. Alternatively an o-nitroamine can be diacylated, the nitro group reduced and the product ringclosed. The groups R and R1 can (if identical) be present as substituents in the starting material or can be introduced into the di-imidazole by standard methods. Examples are given of (1) the reaction between o-phenylene diamine and dl-malic acid in aqueous sulphuric acid to give the sulphate of 1 : 2-di-(benzimidazyl)-ethanol, and the introduction therein of (a) two N-methyl groups; (b) two N-benzyl groups; and (c) one N-hydroxyethyl group, with dimethyl sulphate, benzyl chloride and ethylene chlorhydrin respectively; (2) the reaction between 2-methylamino-aniline and malic acid in aqueous sulphuric acid to give the di-N-methyl-derivative directly. Other amines that can be used are 5-chloro-, 5-methyl- and 5-methoxy-o-phenylene diamines and 1 : 2-naphthylene-diamine.