反应详情

3.8 g of 2-chloro-5-oxo-6-carbethoxy-8-ethyl-5,8-dihydro-pyrido(2,3 -d)pyrimidine and 2.9 g of 1-ethyl-piperazine, dissolved in 50 cm3 of chloroform, are heated under reflux for 2 hours. After cooling, the organic solution is washed with water and dried over MgSO4 ; the solvent is evaporated and the residue is recrystallised from a mixture of isopropyl ether (15 cm3) and benzene (25 cm3) and gives 4.4 g (yield: 93%) of 2-(4'-ethyl-piperazino)5-oxo-8-ethyl-6-carbethoxy-5,8 -dihydro-pyrido(2,3 -d)pyrimidine; melting point 161° C.

1. temperatureare heated
2. temperatureunder reflux for 2 hours
3. temperatureAfter cooling
4. washthe organic solution is washed with water
5. dry with materialdried over MgSO4
6. customthe solvent is evaporated
7. customthe residue is recrystallised from a mixture of isopropyl ether (15 cm3) and benzene (25 cm3)