2-(4-Acetylbenzenesulfonamido)acetic acid → {4-[3E-(2,4-Dimethoxy-5-pyrrolidin-1-ylphenyl)acryloyl]benzenesulfonylamino}acetic acid

Beteiligte Stoffe

Reaktionsschritte

A solution of (4-acetylbenzenesulfonylamino)acetic acid (Ex-26A, 226 mg, 0.878 mmol) and 2,4-dimethoxy-5-pyrrolidin-1-ylbenzaldehyde (Ex-38B, 216 mg, 0.922 mmol) in DMF (8.0 mL) and MeOH (3.6 mL) was treated with lithium methoxide (140 mg, 3.69 mmol) and stirred for 21 h at room temperature under nitrogen. The reaction mixture was quenched with water (10 mL) and extracted ethyl acetate (2×20 mL). The aqueous phase was acidified with 6N HCl to pH3 and was extracted with (3:1) ethyl acetate/THF (6×25 mL). The organic phase was brined, dried over sodium sulfate, and concentrated to a red solid. Precipitation from dichloromethane (5 mL) gave the title compound (33 mg, 8%) as a brown solid, mp 155–158° C. 1H-NMR (300 MHz, DMSO-d6) 12.06 (br s, 1), 8.22 (m, 3H), 8.04 (d, 1H, J=15.3 Hz), 7.89 (d, 2H, J=7.8 Hz), 7.64 (d, 1H, J=15.3 Hz), 7.18 (s, 1H), 6.67 (s, 1H), 3.86 (s, 6H), 3.29 (br s, 2H), 3.16 (br s, 4H), 1.82 (br s, 4H). HRMS (ESI) Calcd. for C23H26N2O7S: 475.1539 [(M+H)+]; Found: 475.1547.

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