methyl 5,6-di(phenyl)-1,2,4-triazine-3-carboxylate 5,6-di(phenyl)-1,2,4-triazine-3-carboxylic acid methyl ester A0810/0037928 MLS000038823 SMR000036960 ZINC00050521 Oprea1_429242 ChemDiv2_002247