6,7-Dimethyl-2-(methylthio)-8H-(1,3,4)thiadiazolo(3,2-a)thieno(2,3-d)pyrimidin-8-one 88753-88-2 8H-(1,3,4)Thiadiazolo(3,2-a)thieno(2,3-d)pyrimidin-8-one, 6,7-dimethyl-2-(methylthio)-