Hydrochloric Acid → p-[2-(3,4-dihydro-4,4-dimethyl-2H-1-benzothiopyran-7-yl)propenyl]benzoic acid

Participants

Reaction Conditions

Reaction Steps

1 g of the thus-obtained ester was dissolved in 20 ml of ethanol and treated with a solution of 1.6 g of potassium hydroxide in 10 ml of water. After heating to 50° C. for 2 hours, the mixture was poured on to ice, acidified with 2N hydrochloric acid and extracted repeatedly with ethyl acetate. The crystalline residue obtained after evaporation was recrystallized from acetic acid. There was obtained 0.6 g of p-[2-(3,4-dihydro-4,4-dimethyl-2H-1 -benzothiopyran-7-yl)propenyl]benzoic acid, m.p. 255°-257° C.

Provenance & Evidence