1-(Phenylsulfonyl)pyrrole-3-sulfonyl chloride synthesis

Yield:881406-26-4 82%

Reaction Conditions:

Stage #1: N-phenylsulfonylpyrrolewith chlorosulfonic acid in acetonitrile at 0 - 20;
Stage #2: with thionyl chloride in acetonitrile; for 3 h;Reflux;

Steps:

A Step A: 1-(Benzenesulfonyl)pyrrole-3-sulfonyl chloride

A solution of 1-(benzenesulfonyl)pyrrole (10 g, 48.3 mmol) in acetonitrile (100 mL) was cooled to 0°C followed by the dropwise addition of chlorosulfonic acid (6.43 mL, 96.5 mmol). The resulting solution was allowed to warm to room temperature and stirred overnight. Thionyl chloride (3.87 mL, 53.1 mmol) was added dropwise followed by heating to reflux for 2 hours. Additional thionyl chloride (704 μL, 9.65 mmol) was added followed by heating at reflux for a further 1 hour. After allowing to cool to room temperature the reaction mixture was quenched by the cautious addition to ice (500 g). The precipitated solid was isolated by vacuum filtration on a sintered funnel, washed with water and dried under vacuum to give the desired product as a dark brown solid (12.1 g, 82%). (0122) 1H NMR (500 MHz, DMSO-d6) d 8.0-8.0 (m, 2H), 7.7-7.8 (m, 1H), 7.6-7.7 (m, 2H), 7.26 (dd, J=2.4, 3.3 Hz, 1H), 7.17 (dd, J=1.6, 2.5 Hz, 1H), 6.31 (dd, J=1.6, 3.2 Hz, 1H). (0123) LC-MS (Method A): R_T = 3.51 min, m/z = 304.1/306.1 [M - H]-.

References:

WO2019/220125,2019,A1 Location in patent:Page/Page column 48