4-Acetylbenzenesulphonamide → 4-[3E-(2,4-dimethoxy-5-pyrrolidin-1-ylphenyl)acryloyl]benzenesulfonamide

Participants

Reaction Steps

Ex-48A: To a solution of 4-acetylbenzenesulfonamide (Ex-35A, 0.13 g, 0.64 mmol) and 2,4-dimethoxy-5-pyrrolidin-1-yl-benzaldehyde (Ex-38B, 0.15 g, 0.64 mmol) in N,N-dimethylformamide (5 mL) was added lithium methoxide (1.0 M in methanol, 1.6 mL, 1.6 mmol). The solution was allowed to stir at ambient temperature for 13 h and then at 40° C. for 2 h. HPLC indicated no further change of starting materials. The reaction mixture was then diluted with water, acidified to pH 5. The resulting precipitate was collected by filtration, washed with water, dried in vacuo. The crude product was slurried in ethanol overnight. The solid was collected by filtration, washed with ethanol, dried in vacuo to give 4-[3E-(2,4-dimethoxy-5-pyrrolidin-1-ylphenyl)acryloyl]benzenesulfonamide (0.16 g, 59%) as a red solid, m.p. 220–222° C. 1H-NMR (300 MHz, DMSO-d6) δ 8.22 (d, J=8.7 Hz, 2H), 8.04 (d, J=16.1 Hz, 1H), 7.93 (d, J=8.7 Hz, 2H), 7.64 (d, J=16.1 Hz, 1H), 7.52 (s, 2H), 7.18 (s, 1H), 6.67 (s, 1H), 3.86 (s, 6H), 3.19–3.17 (m, 4H), 1.84–1.83 (m, 4H). HRMS Calcd for C21H24N2O5S: 416.1408 (M+); Found: 416.1408.

Provenance & Evidence