反应详情

5-Propyl-1H-imidazole-4-carboxylic acid hydrochloride 3 (1.0 g; 5.3 mmol) was added to nitrogen-purged CH3CN (10 mL). Oxalyl chloride (2.5 ml; 29 mmol) was then added, and the mixture was heated to reflux under N2 for 1 h. The brown solution was then allowed to cool, and the product began to precipitate. Ice-cold dry Et2O (30 mL) was added to the reaction flask to complete the precipitation. The green-gold solid was collected by suction filtration, washed with Et2O, and dried under vacuum to afford 0.65 g (71%) of 4. 1H NMR (DMSO-d6): δ 0.90 (t, 3H), 1.70 (m, 2H), 2.90 (t, 2H), 8.70 (s, 1H); 13C NMR (DMSO-d6): δ 13.6, 21.3, 29.4, 118.1, 137.9, 150.46, 155.8.

1. custompurged CH3CN (10 mL)
2. temperaturethe mixture was heated
3. temperatureto reflux under N2 for 1 h
4. temperatureto cool
5. customto precipitate
6. additionIce-cold dry Et2O (30 mL) was added to the reaction flask
7. customthe precipitation
8. filtrationThe green-gold solid was collected by suction filtration
9. washwashed with Et2O
10. customdried under vacuum