N8-(4-Cyclobutyl-1,3-thiazol-2-yl)-3-formyl-2-(3-hydroxypiperidino)-4-oxo-4H-pyrido[1,2-a]pyrimidine-8-carboxamide 以16.3 mg (53%)的产率得到methyl (E)-3-[8-{[(4-cyclobutyl-1,3-thiazol-2-yl)amino]carbonyl}-2-(3-hydroxy-piperidino)-4-oxo-4H-pyrido[1,2-a]pyrimidin-3-yl]-2-propenoate