6-amino-5-hydroxy-1,3-dimethyl-1,8-phenylpyrido[2,3-d]pyrimidine-2,4,7(1H,3H,8H)-trione hydrochloride 、
4-硝基苯甲酰氯 在
PPA 作用下,
反应 4.0h,
以70%的产率得到6,8-dimethyl-2-(4-nitrophenyl)-5-phenyl[1,3]oxazolo-[5',4':4,5]pyrido[2,3-d]pyrimidine-4,7,9(5H,6H,8H)-trione