4H-pyrido[1,2-a]pyrimidine-3-carboxylic acid, 6,7,8,9-tetrahydro-7-methyl-4-oxo-9-(phenylmethylene)-, ethyl ester, (9E)- InChI=1/C19H20N2O3/c1-3-24-19(23)16-11-20-17-15(10-14-7-5-4-6-8-14)9-13(2)12-21(17)18(16)22/h4-8,10-11,13H,3,9,12H2,1-2H3/b15-10 ethyl (9E)-9-benzylidene-7-methyl-4-oxo-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidine-3-carboxylate