Reactions of Isothiocyanates with Cyanothioformamides. Cyclization of 5-Imino-4-thioxo-2-imidazolidones and 5-Imino-2,4-imidazolidinedithiones to 5,7-Dihydrodiimidazopyrazine-2,6(1H,3H)-diones and -dithiones

Article abstract of DOI:10.1021/jo00219a001

N-Methyl- or N-phenylcyanothioformamide (1a,b) reacts with methyl or phenyl isocyanate to provide 5-imino-1,3-disubstituted-4-thioxo-2-imidazolidinones 3a-d.Methyl or phenyl isothiocyanate with 1a,b gives 5-imino-1,3-disubstituted-2,4-imidazolidinedithion