Potassium Hydroxide → HCID 22154304, compound

Participants

Reaction Steps

6-chloro-3,4-dihydro-2H-1-benzpyran-4-ylidene-acetic acid methyl ester (2.0 g.) was reduced with hydrogen using a 10% Pd-charcoal catalyst (0.20 g.) by stirring at 25° C. in ethyl acetate for 4 hours. The reduction product, 6-chloro-3,4-dihydro-2H-1-benzopyran-4-acetic acid methyl ester (1.0 g.), was heated for 3 days at reflux temperature with potassium hydroxide (2.4 g.) in 25 ml. water. The solution was acidified and extracted with chloroform. Recrystallization from cyclohexane gave 6-chloro-3,4-dihydro-2H-1-benzopyran-4-acetic acid (650 mg. 60%), m.p. 115°-117° C.

Provenance & Evidence