Ammonium Chloride → 1-(3-Benzyloxy-2,2-difluoropropyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Participants

Reaction Conditions

Reaction Steps

A solution of 1-(3-benzyloxy-2,2-difluoropropyl)-4-iodo-1H-pyrazole (Compound 59F, 1.8 g, 4.7 mmol) in THF (40 mL) was cooled to −78° C., treated with iPrMgCl (4.75 mL, 9.5 mmol, 2M) and the temperature was raised to −40° C. After 20 min stirring at −40° C., reaction mixture was cooled to −78° C. and treated with 2-methoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (0.091 mL, 0.56 mmol). The reaction mixture was allowed to warm to RT, treated with sat. aq. ammonium chloride (20 mL) and extracted with ethyl acetate (20 mL). The organic layer was dried over Na2SO4, filtered and concentrated to give 1.56 g (89%) of desired product as an oil. 1H NMR (500 MHz, CDCl3) δ 7.81 (s, 1H), 7.78 (s, 1H), 7.36-7.33 (m, 5H), 4.64-4.59 (m, 4H), 3.56 (t, J=12 Hz, 2H), 1.26 (s, 12H).

Provenance & Evidence