反应详情

温度

145 °C

A solution of molten acetamide (1.58 g, 26.7 mmol) heated to 90° C. was treated with a mixture of 2-bromo-5-nitropyrazine (1.34 g, 6.58 mmol), methanesulfonamide (1.88 g, 19.7 mmol), and potassium carbonate (2.30 g, 16.6 mmol). The resulting mixture was quickly brought to 145° C. The resulting solution was stirred at 145° C. for 30 min. At this time, the reaction was cooled to 25° C. and then was treated with water (4 mL). This solution was cooled to 0° C. and then was treated with a 1N aqueous hydrochloric acid solution until the pH of the solution was adjusted to pH=8. This solution was treated with charcoal and was filtered through a pad of celite (9/1 methylene chloride/methanol wash). The filtrate was partitioned, and the aqueous layer was extracted with a solution of 9/1 methylene chloride/methanol. The combined organic layers were dried over sodium sulfate, filtered, and concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230–400 mesh, ethyl acetate) afforded N-(5-nitro-pyrazin-2-yl)-methanesulfonamide (583.9 mg, 40.6%) as a yellow solid: mp 204–207° C.; EI-HRMS m/e calcd for C5H6N4O4S (M+H)+ 219.0183, found 219.0185.

1. customwas quickly brought to 145° C
2. temperatureAt this time, the reaction was cooled to 25° C.
3. temperatureThis solution was cooled to 0° C.
4. filtrationwas filtered through a pad of celite (9/1 methylene chloride/methanol wash)
5. customThe filtrate was partitioned
6. extractionthe aqueous layer was extracted with a solution of 9/1 methylene chloride/methanol
7. dry with materialThe combined organic layers were dried over sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated in vacuo