反应详情

A stirred solution of commercially available 5-amino-1H-imidazole-4-carboxamide (25 g, 198 mmol) in methanesulfonic acid (107 ml) and ethanol (400 ml) was stirred at reflux conditions for 12d, evaporated and water (300 ml) was added. While stirring and cooling (ice/water) sodium hydroxide solution (32%) was added until pH=6 was reached. The water layer was saturated with sodium chloride and extracted with ethyl acetate (3×200 ml). The combined organic layers were dried (MgSO4), evaporated and the crude product purified crystallization (ethyl acetate/ethanol) to yield 5-amino-1H-imidazole-4-carboxylic acid ethyl ester (13.7 g, 45%) as a light brown solid. MS (EI) 155.1 [(M)+]; mp 178° C.

1. customevaporated
2. additionwater (300 ml) was added
3. temperaturecooling (ice/water) sodium hydroxide solution (32%)
4. additionwas added until pH=6
5. extractionextracted with ethyl acetate (3×200 ml)
6. dry with materialThe combined organic layers were dried (MgSO4)
7. customevaporated
8. customthe crude product purified
9. customcrystallization (ethyl acetate/ethanol)