Vanillin → Vanillin acetate

Participants

Reaction Steps

Triethylamine (2.8 liters, 20.1 moles) was added dropwise to a solution of vanillin (2.00 kg., 13.15 moles) and acetic anhydride (2.6 liters, 27.5 moles) in methylene chloride (11.3 liters) maintaining temperature below 25° C. After adding 4-dimethylaminopyridine (20 g.) the solution was stirred at room temperature for 30 minutes. The reaction mixture was washed twice with water, followed by 20% (w/w) hydrochloric acid and brine. The organic layer was dried over sodium sulfate and concentrated in vacuo to 8 liters. Hexane (15 liters) was added slowly while removing remaining methylene chloride. After cooling, 2.45 kg. (96% yield) product was filtered off. Recrystallization of a small sample from anhydrous ether gave the acetate as fine yellow needles, M.P. 76°-78° C.

Provenance & Evidence