反应详情

温度

40 °C

To a suspension of ethyl 5-amino-1,3,4-thiadiazole-2-carboxylate (2 g, 11.55 mmol) in methanol (15 mL) was added cyclopropylamine (1.5 mL, 21.65 mmol). The mixture was stirred at room temperature for 1 h and at 40° C. for 1.5 h. Additional cyclopropylamine (2 mL) was added. After 3 h at 40° C., 1 h at 50° C. and 20 min at 70° C., the mixture was concentrated to half the volume, diluted with water (2.5 mL), heated to boil to give a clear solution and cooled to room temperature. The solid was filtered, washed with cold methanol, and dried to give 5-amino-N-cyclopropyl-1,3,4-thiadiazole-2-carboxamide as yellow crystals (1.52 g, 72% yield). MS (ES+) m/z: 185 (M+H); LC retention time: 0.87 min (analytical HPLC Method A).

1. waitAfter 3 h at 40° C.
2. concentration1 h at 50° C. and 20 min at 70° C., the mixture was concentrated to half the volume
3. additiondiluted with water (2.5 mL)
4. temperatureheated
5. customto give a clear solution
6. temperaturecooled to room temperature
7. filtrationThe solid was filtered
8. washwashed with cold methanol
9. customdried