Oxalyl chloride → 5-propyl-1H-imidazole-4-carbonyl Chloride
Reaction equation
Cl.[CH2:2]([C:5]1[NH:9][CH:8]=[N:7][C:6]=1[C:10]([OH:12])=O)[CH2:3][CH3:4].C(Cl)(=O)C([Cl:16])=O>>[CH2:2]([C:5]1[NH:9][CH:8]=[N:7][C:6]=1[C:10]([Cl:16])=[O:12])[CH2:3][CH3:4]Participants
3
Procedure
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.