Acetic Acid → 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenyl acetic acid

Participants

Reaction Steps

To a solution of 5-methoxy-2-methyl-3-indenylacetic acid (1a) (3.95 g) in 90% methanol (24 ml) containing 85% potassium hydroxide (2.7 g) was added a solution of p-aminosulfonylbenzaldehyde (3.70 g) in 90% methanol (24 ml). The resulting mixture was refluxed under nitrogen for 4-6 hours. A solution of 50% aqueous acetic acid (50 ml) was then added to the reaction mixture during 40 minutes at 50°-60° C. The crystals were collected after aging at 15° C. for 1 hour. The crude product was recrystallized five times from acetone-hexane to give pure Z form of 1-(4-aminosulfonylphenyl)methylene-5-methoxy-2-methyl-1H-3-indenylacetic acid (2a) (4.0 g, 57%): m.p. 224°-225° C.; Rf =0.45 (silica gel, 10% MeOH in CHCl3 developed 3-4 times).

Provenance & Evidence