Interaction of methyl (2-methylsulfanyl-6-phenyl-4-thioxopyrimidin-3(4H)-yl)acetate with hydrazine hydrate

Abstract

Methyl (2-methylsulfanyl-6-phenyl-4-thioxopyrimidin-3(4H)-yl)acetate (2) reacted with hyd­razine hydrate at room temperature in 1-butanol to give the corresponding hydrazide 3.
The same reaction at reflux in different solvents (methanol, acetonitrile, n-butanol or dimethylformamide) underwent thermally induced cyclization to yield 1-amino-7-phe­nyl-5-thioxo-1,5-dihydroimidazo[1,2-a]pyrimidin-2(3H)-one (4) and 6-hydrazino-8-phe­nyl-2H-pyrimido[6,1-c][1,2,4]triazin-3(4H)-one (5). The latter 5 was synthesized by an alternative method from 4-hydrazino-6-phenyl-2-methylsulfanylpyrimidine. New com­pounds are characterized by 1H, 13C NMR, IR spectroscopy and analytical data.