Hexane → 4-[4-(4-Fluorophenyl)thien-3-yl]benzenesulfonamide

Participants

Reaction Conditions

Reaction Steps

To a solution of 3-(4-methylsulfonylphenyl)-4-(4-fluorophenyl)thiophene (0.332 g, 1.0 mmol) from Step 5 in THF (8 mL) at -70° C. under nitrogen was added 1.6M n-butyllithium in hexane (0.66 mL, 1.05 mmol) slowly, via syringe, and the mixture stirred at -70° C. for 20 minutes and then at room temperature (25° C.) for 1 hour. After cooling to -70° C., a 1.0M solution of tri-n-butyl borane in THF (1.15 mL, 1.15 mmol) was added and the mixture allowed to warm slowly to 0° C. for 1 hour, warmed to room temperature for 2 hours, and finally stirred at reflux overnight (18 hours). After cooling to room temperature and stirring for 3 hours, water (0.8 mL) was added followed by sodium acetate (0.6 g) and hydroxylamine-O-sulfonic acid (0.41 g). After stirring at room temperature overnight, the mixture was poured into 3 volumes of ethyl acetate, and the organic layer washed with water and brine and dried over MgSO4. After solvent removal, the white solids (a mixture of product and starting material) were separated via flash chromatography on silica gel using a 15% ethyl acetate/85% toluene eluant to yield 4-[4-(4-fluorophenyl)thien-3-yl]benzenesulfonamide as a white solid (59 mg, mp 194°-195° C.). Anal. Calc'd for C16 H12NO2S2F: C, 57.64; H, 3.63; N, 4.20. Found: C, 57.37; H, 3.69; N, 3.99.

Provenance & Evidence