3-Bromo-4-trifluoromethoxybenzenesulfonyl chloride synthesis

Yield:-

Reaction Conditions:

with chlorosulfonic acid in dichloromethane at 0 - 20; for 0.5 h;

Steps:

I.a.9

a.9 3-Bromo-4-trifluoromethoxy-benzenesulfonyl chloride2.0 g of 1-bromo-2-(trifluoro-methoxy)benzene (8.3 mmol) were dissolved in 30 ml of dichloromethane. At 0-5⁰C, 1.06 g of chlorosulfonic acid (9.13 mmol), dissolved in 3 ml of dichloromethane, were added dropwise. The reaction mixture was stirred for 30 min at room temperature. Additional 5.5 equivalents of chlorosulfonic in dichloromethane were added to drive the reaction to completion. Standard work-up was followed and silica gel chromatography with n-heptane- dichloromethane (6:4) as eluent gave 2.19 g of the title compound.¹H-NMR (CDCI₃, 400 MHz): δ [ppm] 8.3 (d, 1 H), 8.05 (dd, 1 H), 7.5 (dd, 1 H).

References:

WO2006/40176,2006,A1 Location in patent:Page/Page column 94