Acetic Anhydride → 1-Acetyl-4-methylimidazole

Participants

Reaction Steps

The 1-Acetyl-4-methylimidazole intermediate was prepared by making a mixture of 4-methylimidazole (82.1 g, 1.0 mol)) and acetic anhydride (190 mL, 2.0 mol) and refluxing for 15 min after which time 150 mL of solvent was removed by distillation at atmospheric pressure (head temperature 125° C.) over a 1 h period. The remaining acetic anhydride was removed at 50° C./0.5 mm and the residual liquid was crystallized from ether (150 mL) at -20° C. to give 85.5 g of 1-acetyl-4-methylimidazole product, m.p. 49°-51° C.

Provenance & Evidence