反应详情

7-Cyano-1H-imidazo[1,2-b]pyrazole (3 g) was added to conc. sulfuric acid under ice-cooling. The mixture was stirred at room temperature for 45 minutes. The reaction mixture was cooled at 0°-5° C. and carefully poured into ice water (30 ml). The aqueous solution was neutralized with conc. ammonium hydroxide solution and stirred for 1 hour under ice-cooling. The precipitate was collected, washed with cold water and dried over phosphorus pentoxide in vacuo to give 7-carbamoyl-1H-imidazo[1,2-b]pyrazole (3.45 g).

1. temperaturecooling
2. temperatureThe reaction mixture was cooled at 0°-5° C.
3. stirringstirred for 1 hour under ice-
4. temperaturecooling
5. customThe precipitate was collected
6. washwashed with cold water
7. dry with materialdried over phosphorus pentoxide in vacuo