反应详情

To diphenyl ether (16ml) kept at 250°-255° C. was added with stirring diethyl N-[2-(4-acetyl-1-piperazinyl)-4-pyrimidinyl]-aminomethylenemalonate (2.0g). The mixture was gently refluxed for 10 minutes, and then allowed to cool to room temperature. To the mixture was added n-hexane (12ml). The resulting precipitate was collected, washed with ethanol, and recrystallized from ethanol to yield ethyl 2-(4-acetyl-1-piperazinyl)-5,8-dihydro-5-oxopyrido[2,3-d] pyrimidine-6-carboxylate (1.52 g), m.p. 300°-302° C. (decomp.).

1. customkept at 250°-255° C.
2. temperatureThe mixture was gently refluxed for 10 minutes
3. customThe resulting precipitate was collected
4. washwashed with ethanol
5. customrecrystallized from ethanol