反应详情

A solution of 2-chloro-3-nitropyrazine (9.1 g, 57 mmol) in chloroform (100 ml) was added dropwise over 45 minutes to a cooled solution of piperazine-2-one (5.71 g, 57 mmol) and triethylamine (8.0 ml, 57 mmol) in isopropanol (120 ml). After addition was complete, the reaction mixture was allowed to warm to 20°-25° and was stirred at this temperature for 20 hours. The precipitate was removed by filtration and recrystallized from methanol-ethyl acetate-hexane to give 6.96 g (54.7%) of product, m.p. 178°-179°.

1. additionAfter addition
2. temperatureto warm to 20°-25°
3. customThe precipitate was removed by filtration
4. customrecrystallized from methanol-ethyl acetate-hexane