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 at ambient temperature with stirring. The resulting stirred solution was heated under reflux and an argon atmosphere for 4 hours. Water (10 ml) was added at ambient temperature and the solvent removed by evaporation. A further volume of water (10 ml) was added and the aqeous phase was extracted with dichloromethane (3×50 ml). Combined organic extracts were dried (MgSO4) and evaporated to give 2-amino-5-chloro-3-methoxypyrazine (1.28 g), m.p. 102°-103° C.; 1H NMR (d6DMSO): 3.90 (s, 3H), 7.53 (s, 1H); mass spectrum (+ve CI): 160 (M+H)+.

1. stirringThe resulting stirred solution
2. temperaturewas heated
3. temperatureunder reflux
4. customthe solvent removed by evaporation
5. additionA further volume of water (10 ml) was added
6. extractionthe aqeous phase was extracted with dichloromethane (3×50 ml)
7. dry with materialCombined organic extracts were dried (MgSO4)
8. customevaporated