反应详情

A solution of 2,6-diiodopyrazine (6 g, 18.1 mmol) in methanol (50 ml) and dimethylamine (40% aqueous solution, 200 ml) was heated at reflux for 1 h. The methanol was removed under vacuum, the aqueous saturated with potassium carbonate and extracted with dichloromethane (3×100 ml). The combined extracts were dried (Na2SO4), evaporated and the residue purified by chromatography through silica-gel eluting with dichloromethane. The product (4 g) was obtained as a low melting solid, m.p. 46°-48° C., m/e 249 (M+); δ (360 MHz, CDCl3) 3.10 (6H, s, 2×Me); 7.87 (1H, s, pyrazine-H); 8.01 (1H, s, pyrazine-H).

1. temperatureat reflux for 1 h
2. customThe methanol was removed under vacuum
3. extractionthe aqueous saturated with potassium carbonate and extracted with dichloromethane (3×100 ml)
4. dry with materialThe combined extracts were dried (Na2SO4)
5. customevaporated
6. customthe residue purified by chromatography through silica-gel
7. washeluting with dichloromethane