反应详情

4.77 g. of 2,6-dimethyl-3-ethyl-4-oxo-4H-pyrido[1,2-a]pyrimidine hydrochloride are dissolved in 50 ml. of water and the pH-value of the mixture is adjusted to 7 with a 10% aqueous sodium carbonate solution. The reaction mixture is shaken with four 25-ml. portions of chloroform, the chloroform extracts are combined, dried over medium sulphate and evaporated. Ethyl acetate is distilled through the residue. 4.0 g. (99%) of 2,6-dimethyl-3-ethyl-4-oxo-4H-pyrido[1,2-a]pyrimidine are obtained, melting at 127° to 128° C. after recrystallization from a mixture of ethanol and ether.

1. dry with materialdried over medium sulphate
2. customevaporated
3. distillationEthyl acetate is distilled through the residue