Water → Pilocarpic acid ethyl ester

Participants

Reaction Steps

9.80 mmoles of ethylbromide (1068 mg) were added dropwise within about an hour to a solution containing 9.80 mmoles (2432 mg) of pilocarpic acid sodium salt in 60 ml of dimethyl sulfoxide. The solution was stirred at room temperature for 48-72 hours and poured into 100 ml of distilled water. The mixture was extracted with two portions of each 150 ml of ethyl acetate. The combined ethyl acetate extracts were washed with 150 ml of distilled water, with 150 ml of 2% sodium bicarbonate solution and with 150 ml of distilled water. The ethyl acetate extracts were dried on calcium sulfate (30 min) and the ethyl acetate evaporated under reduced pressure, and the pilocarpic acid ethyl ester obtained was crystallized from a chloroform/ petroleum ether-mixture, whereby 448 mg (1.76 mmoles) of the ester were obtained.

Provenance & Evidence