Imidazole 4(5)-dithiocarboxylic acids or salts

Abstract

Disclosed is an imidazole-4(5)-dithiocarboxylic acid compound represented by the following general formula: ##STR1## wherein R.sub.2 stands for a hydrogen atom or a monovalent hydrocarbon group having up to 20 carbons, R.sub.4 stands for a hydrogen atom or an alkyl group having up to 4 carbon atoms, and X stands for a hydrogen atom or an alkali metal atom. This compound has an excellent rust preventive action to silver. This compound is prepared according to a process which comprises reacting an imidazole compound represented by the following general formula: ##STR2## wherein R.sub.2 and R.sub.4 are as defined above, with carbon disulfide and an alkali metal hydroxide in the presence of a solvent, and if necessary, acidifying the obtained imidazole compound.

Dependencies are inferred from the claim text.