1,2,4-Triazolo(3,4-a)phthalazine, 6-(ethylsulfonyl)-3-phenyl- 6-(Ethylsulfonyl)-3-phenyl-1,2,4-triazolo(3,4-a)phthalazine 6-(Ethylsulphonyl)-3-phenyl-1,2,4-triazolo(3,4-a)phthalazine 87540-67-8