1,2,4-Triazinium, 2,5-dihydro-1-methyl-5-oxo-3-phenyl-, hydroxide, inner salt 1-Methyl-3-phenyl-1,2,4-triazin-5-one 1-Methyl-3-phenyl-1,2-4-triazinium-5-olate 113342-81-7 MPTO