Reactions of β-imino-nitriles and -esters with carbon disulphide. A new synthesis and some reactions of 2-cyano-3-imino-dithiocarboxylic acids

Abstract

Treatment of a series of β-imino-nitriles with carbon disulphide and sodium t-pentyl oxide at room temperature gave the corresponding 2-cyano-3-imino-dithiocarboxylic acids, accompanied in some cases by pyrimidine-2,4-dithiones. β-lmino-β-arylpropiononitriles, when treated with carbon disulphide in dimethylformamide at low temperature, afforded 1,3-thiazine-2,6-dithiones. When an excess of sodium t-pentyl oxide was used in this reaction, β-iminobutyronitrile yielded pyrido[4,3-d][1,3]thiazine-2,4,5,7(1H,8H)-tetrathione. β-lmino-β-phenylpropiononitrile, under the same conditions, gave a 1,5-diazocine-2,6(1H,5H)-dithione. β-lmino-esters in this reaction, afforded 1,3-thiazine-2,6-dithiones. Reactions of 2-cyano-3-imino-dithiocarboxylic acids with methyl and phenyl isocyanates, ethyl and phenyl isothiocyanates, picryl chloride, and hydrazine have also been studied.