N,N-Diethylaniline → 8-allyl-7-hydroxy-4-methyl-chromen-2-one

Participants

Reaction Steps

Crude 7-allyloxy-4-methylcoumarin (83.5 g, 0.381 mol) was dissolved in 250 ml of diethyl aniline with heating, and the solution was allowed to reflux for two hours. After the solution had cooled and some product had precipitated, petroleum ether (b.p. 30°-60° C., 760 ml) was added. A brown precipitate formed and was collected by filtration, washed with three small portions of petroleum ether, and dried in vacuo to obtain the crude product. Recrystallization from 600 ml of 95% EtOH gave the pure product (53.5 g, 74% recovery, 65% yield) of mp 192.5°-195.0° C. (lit. 193°-194° C.). TLC showed only a single spot.

Provenance & Evidence