2-(ethylsulfonyl)-5-methyl-7H-[1,3,4]thiadiazolo[3,2-a]pyrimidin-7-one InChI=1/C8H9N3O3S2/c1-3-16(13,14)8-10-11-5(2)4-6(12)9-7(11)15-8/h4H,3H2,1-2H