Benzoic Acid → 2-{4-[4-(2,4-Dioxothiazolidin-5-ylidenemethyl)-phenoxy]-phenyl}-3-p-tolylacrylic acid

Participants

Reaction Steps

To a solution of 39 (4.0 g, 11.2 mmol), thiazolidine-2,4-dione (1.31 g, 11.2 mmol), and benzoic acid (1.64 g, 13.4 mmol) in 100 mL toluene was added piperidine (1.66 mL, 16.8 mmol). The mixture was vigorously refluxed with Dean Stark apparatus for 1.5 h under argon then cooled to room temperature. 5% HCl was added to pH 1. The solid was filtered, recrystallized out of toluene, filtered, and washed with hexane before drying under vacuum to a yellow solid (quantitative). 1H NMR (400 MHz, DMSO-d6) δ 12.70 (br s, 1H), 12.59 (br s, 1H), 7.80 (s, 1H), 7.75 (s, 1H), 7.67 (d, J=8.8 Hz, 2H), 7.22 (d, J=9.2 Hz, 2H), 7.18 (d, J=7.6 Hz, 2H), 7.12 (d, J=9.2 Hz, 2H), 7.07 (d, J=8.0 Hz, 2H), 6.99 (d, J=8.0 Hz, 2H), 2.25 (s, 3H).

Provenance & Evidence