5-Methyl-4-phenyl-2,4-dihydro-3H-1,2,4-triazol-3-one(1,5-Dihydro-3-methyl-5-oxo-4H-1,2,4-triazol-4-yl)benzene4,5-Dihydro-3-methyl-5-oxo-4-phenyl-1H-1,2,4-triazole2,4-Dihydro-5-methyl-4-phenyl-3H-1,2,4-triazol-3-one3-Methyl-4-phenyl-1H-1,2,4-triazol-5(4H)-one