Reaction of 3,4-Diaminopyridazine with α,β-Dicarbonyl compounds, carbon disulfide and urea, and methylation of some of the products

Abstract

3,4-Diaminopyridazine has been shown to condense with benzil, diacetyl and phenylglyoxal to give 6,7-diphenyl-, 6,7-dimethyl- and 6(7)-phenyl- pyrazino[2,3-c]pyridazine, respectively.    

Syntheses of 2-, 5- and 7-methyl-6-methylthioimidazo[4,5- c]pyridazine have been described. Methylation of 6-mercaptoimidazo[4,5- c]pyridazine with diazomethane gave 1- and 7-methyl-6- methylthioimidazo[4,5-c]pyridazine but methyl iodide gave 1- and 2- methyl-6-methylthioimidazo-[4,5-c]pyridazine. Diazomethane methylation of 6-hydroxyimidazo[4,5-c]pyridazine gave three dimethyl derivatives of which one was identified as 6-methoxy-1-methylimidazo[4,5-c]pyridazine.