Coumarin-3-Carboxylic Acid → Coumarin-3-carbonyl chloride

Participants

Reaction Steps

Coumarin-3-carboxylic acid (2.1 g, 10 m mole) was suspended in dry dichloromethane (10 ml) and heated at reflux for 2 h with thionyl chloride (5 ml). After this time a small amount of insoluble material was filtered off and petroleum ether 60°-80° C. (35 ml) was added to the filtrate. The acid chloride was filtered, washed with ether and dried (1.63 g, 71%), mp 138°-41° C.; νmax (CHCl3) 1790, 1740, 1610, 1570 cm-1 ; δ (CDCl3) 7.30-8.10 (4H, m, phenyls), 8.95 (1H, s, coumarin 4-H).

Provenance & Evidence