3-(Trifluoromethyl)benzenesulfonyl chloride → N-(2-Bromo-5-chloro-pyridin-3-yl)-3-trifluoromethyl-benzenesulfonamide

Participants

Reaction Steps

To a stirred solution of 2-bromo-5-chloro-pyridin-3-ylamine (2.07 g, 10.0 mmol) in anhydrous pyridine (20 mL) was added 3-(trifluoromethyl)benzenesulfonyl chloride (4.90 g, 20.0 mmol) and the progress of the reaction was followed by LCMS. The reaction mixture was stirred overnight (18 h), then concentrated to dryness. The residue was dissolved in THF (20 mL) and stirred 18 h with 1M TBAF (20 mL) in THF to cleave the bis-sulfonamide. The THF was subsequently evaporated and the residue was dissolved in ethyl acetate. The organic phase was then washed with water (2×100 mL), brine, and then dried (MgSO4), filtered, and concentrated under reduced pressure. The residue was purified by chromatography on silica gel using ethyl acetate-hexane to provide N-(2-Bromo-5-chloro-pyridin-3-yl)-3-trifluoromethyl-benzenesulfonamide as a white crystalline solid. MS m/z 417.1 (M+H).

Provenance & Evidence