Dimethyl Sulfate → 1,4-Dimethyl-5-nitro-1H-imidazole

Participants

Reaction Conditions

Reaction Steps

127 parts of 4-methyl-5-nitroimidazole is heated under reflux with 350 parts of formic acid and 126 parts of dimethyl sulfate for 4 hours. The formic acid is distilled off in vacuo and the residue is dissolved in 500 parts of water and adjusted to pH 1.8 with aqueous ammonia solution. The mixture is cooled to 5° C. and the unreacted 4-methyl-5-nitroimidazole is suction filtered. The filtrate is adjusted to pH 10 with aqueous ammonia solution and is continuously exhaustively extracted with ethyl acetate. The extract is evaporated in vacuo. The oily residue crystallizes on standing. 47 parts of unreacted 4-methyl-5-nitroimidazole and 66 parts of 1,4-dimethyl-5-nitroimidazole melting at 45° C. are obtained; this is equivalent to a yield of 74% of theory.

Provenance & Evidence