10H-(1)Benzothieno(2,3-d)-1,3,4-thiadiazolo(3,2-a)pyrimidin-10-one, 2-(methylthio)- 110543-87-8 2-(Methylthio)-10H-(1)benzothieno(2,3-d)-1,3,4-thiadiazolo(3,2-a)pyrimidin-10-one