4-methyl-3-(8-methyl-2-methylsulfanyl-7-oxo-7,8-dihydro-pyrido[2,3-d]pyrimidin-6-yl)-benzoic acid methyl ester 、 Potassium;oxido hydrogen sulfite 、 、
4-氨基四氢吡喃 以to give 4-methyl-3-[8-methyl-7-oxo-2-(tetrahydro-pyran-4-ylamino)-7,8-dihydro-pyrido[2,3-d]pyrimidin-6-yl]-benzoic acid methyl ester的产率得到4-methyl-3-[8-methyl-7-oxo-2-(tetrahydro-pyran-4-ylamino)-7,8-dihydro-pyrido[2,3-d]pyrimidin-6-yl]-benzoic acid methyl ester