Methanol → 4-(5-(4-chlorophenyl)-3-hydroxymethyl-1H-pyrazol-1-yl]benzenesulfonamide

Participants

Reaction Steps

4-[4-(Aminosulfonyl)phenyl-5-(4-chlorophenyl)-1H-pyrazole-3-carboxylic acid from Step 3 (3.8 g, 10 mmol) and tetrahydrofuran (100 mL) was stirred at room temperature during the dropwise addition of 1.0 M borane-tetrahydrofuran complex (30 mL, 30 mmol). The mixture was heated to reflux for 16 hours. The solution was cooled and methanol was added dropwise until gas evolution ceased. Ethyl acetate (100 mL) was added and the solution was washed with 1N hydrochloric acid, brine, and sat. aq. sodium bicarbonate solution, dried over magnesium sulfate, filtered and concentrated. The resultant material was recrystallized from ethanol:water to yield 4-[5-(4-chlorophenyl)-3-hydroxymethyl-1H-pyrazol-1-yl]benzenesulfonamide (2.6 g, 71%) as a white solid: mp 192-194° C.; 1H NMR (DMSO-d6/300 MHz) δ 7.81 (d, J=8.7 Hz, 2H), 7.46 (d, J=8.4 Hz, 2H), 7.42 (brs, 2H), 7.40 (d, J=8.7 Hz, 2H), 7.26 (d, J=8.4 Hz, 2H), 6.63 (s, 1H), 5.35 (t, J=8.0 Hz, 1H), 4.50 (d, J=8.0 Hz, 2H). Anal. Calc'd for C16H14N3SO2Cl: C, 52.82; H, 3.88; N, 11.55. Found: C, 52.91; H, 3.88; N, 11.50.

Provenance & Evidence