反应详情

40.0 g. (0.127 mole) of 9-bromo-6-methyl-4-oxo-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidine-3-carboxylic acid ethyl ester are dissolved in 80 ml. of dimethylsulfoxide and 26 ml. (0.285 mole) of aniline are added. The solution is allowed to stand at room temperature for 3-4 days. The mixture is then diluted with 100 ml. of water, shaken out with 3×50 ml. of benzene. The combined organic layers are dried with calcinated sodium sulfate and evaporated in vacuo. The residue is recrystallized from ethanol and thus 24.5 g. (59.3%) of 9-(phenyl-amino)-6-methyl-4-oxo-6,7-dihydro-4H-pyrido[1,2-a]pyrimidine-3-carboxylic ethyl ester is obtained, melting point: 119°-120° C.

1. additionThe mixture is then diluted with 100 ml
2. dry with materialThe combined organic layers are dried with calcinated sodium sulfate
3. customevaporated in vacuo
4. customThe residue is recrystallized from ethanol and thus 24.5 g