反应详情

Sodium (2.82 g) was dissolved in dry methanol (50 ml) under argon and 2-amino-3-bromo-5-chloropyrazine (1.68 g) was added in small portions with stirring. The stirred solution was heated at reflux under an atmosphere of argon for 4 hours. The solution was allowed to cool to ambient temperature and water (10 ml) was added. Volatile material was removed by evaporation and water (10 ml) was added to the residue. The mixture was extracted with dichloromethane (3×50 ml) and the combined extracts were dried (MgSO4) and evaporated to give 2-amino-5-chloro-3-methoxypyrazine (1.28 g), m.p. 102-103° C.; 1H NMR (d6 -DMSO): 3.90 (s, 3H), 7.53 (s, 1H); mass spectrum (+ve CI): 160 (M+H)+.

1. temperatureThe stirred solution was heated
2. temperatureat reflux under an atmosphere of argon for 4 hours
3. customVolatile material was removed by evaporation and water (10 ml)
4. additionwas added to the residue
5. extractionThe mixture was extracted with dichloromethane (3×50 ml)
6. dry with materialthe combined extracts were dried (MgSO4)
7. customevaporated