Sodium hydride → 1-(3-benzyloxy-2,2-difluoropropyl)-4-iodo-1H-pyrazole

Participants

Reaction Steps

A cold (0° C.) solution of 4-iodo-1H-pyrazole (10.1 g, 51.8 mmol) in DMF (20 mL) was treated with NaH (1.56 g, 38.82 mmol, 60%) and allowed to warm to RT. After 1 h, the reaction mixture was treated with methanesulfonic acid 3-benzyloxy-2,2-difluoropropyl ester (Compound 59G, 2.0 g, 6.47 mmol) and was stirred for 24 h at 70° C. The reaction mixture was poured into chilled sat. aq. ammonium chloride (20 mL) and extracted with ethyl acetate (100 mL). The organic layer was washed with water (5×30 mL), dried over Na2SO4, filtered, concentrated and purified by column chromatography (SiO2, 30% ethyl acetate/hexanes) to give 1.8 g (72%) of the title compound as a white solid. 1H NMR (500 MHz, CDCl3) δ 7.32-7.38 (m, 7H), 4.63 (s, 2H), 3.89 (s, J=12.5 Hz, 2H), 3.77 (t, J=12.5 Hz, 2H).

Provenance & Evidence