反应详情

4-[4-(Aminosulfonyl)phenyl-5-(4 chlorophenyl)-1H-pyrazole-3-carboxylic acid from Step 2 (3.8 g, 10 mmol) and tetrahydrofuran (100 mL) were stirred at room temperature during dropwise addition of 1.0 M borane-tetrahydrofuran complex (30 mL, 30 mmol). The mixture was held at reflux for 16 hours. The mixture was cooled and methanol was added dropwise until gas evolution ceased. Ethyl acetate (100 mL) was added and the mixture was washed with 1N hydrochloric acid, brine, sat. aq. sodium bicarbonate solution, and water, dried over magnesium sulfate, filtered and concentrated. The resultant alcohol was recrystallized from ethanol:water to yield a white solid (2.6 g, 71%): 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; C, 52.91; H, 3.88; H, 3.88; N, 11.55; N, 11.50.

1. temperatureat reflux for 16 hours
2. temperatureThe mixture was cooled
3. washthe mixture was washed with 1N hydrochloric acid, brine, sat. aq. sodium bicarbonate solution, and water
4. dry with materialdried over magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated
7. customThe resultant alcohol was recrystallized from ethanol