英文别名vardenafil impurity 1; 2-(2-ethoxyphenyl)-5-methyl-7-carboethoxy-imidazo[5,1-f][1,2,4]triazin-4(3H)-one; Vardenafil Impurity 16; Imidazo[5,1-f][1,2,4]triazine-7-carboxylic acid, 2-(2-ethoxyphenyl)-1,4-dihydro-5-methyl-4-oxo-, ethyl ester; Ethyl 2-(2-ethoxyphenyl)-5-methyl-4-oxo-3,4-dihydroimidazo[5,1-f][1,2,4]triazine-7-carboxylate 
