Abstract Ethyl 3, 4-dihydro-4-methyl-3-thioxo-2-quinoxalinylacetate has been prepared by thionation of the 3-oxo derivative. The mechanism is discussed of the reaction of this ester with diethylamine giving the two non-isomerizing ketimine-enamine tautomers and 1, 2- dihydro-1, 3-dimethyl-2-thioxoquinoxaline. Structure has been studied of the reaction product of both this derivative and its 3-oxo analogue with sodium hydride in dimethyl ...
