REACTION OF 6-CHLORO-2-[1-METHYL-2-(N-METHYLTHIOCARBAMOYL)]-HYDRAZINOQUINOXALINE 4-OXIDE WITH DIMETHYL ACETYLENEDICARBOXYLATE

The reaction of 6-chloro-2-(1-methylhydrazino)quinoxaline 4-oxide 4a with methyl or phenyl isothiocyanate gave 6-chloro-2-(1-methyl-2-(N-methylthiocarbamoyl)hydrazino]quinoxaline 4-oxide 7a or 6-chloro-2-[1-meth-yl-2-(N-phenylthiocarbamoyl)hydrazino]quinoxaline 4-oxide 7b, respectively, whose reaction with dimethyl acetylenedicarboxylate afforded 6-chloro-2-(N-methyl-N-(5-methoxycarbonylmethylene-3-methyl-4-oxo-2-thi-oxoimidazolidin-1-yl)]aminoquinoxaline 4-oxide 8a or 6-chloro-2-[N-methyl-N-(5-methoxycarbonylmethylene-4-oxo-3-phenyl-2-thioxoimidazolidin-1-yl)]aminoquinoxaline 4-oxide 8b, respectively.