Ammonium Chloride → 1-[2-(oxan-2-yloxy)ethyl]-4-(tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-iodo-1-(2-(tetrahydro-2H-pyran-2-yloxy)ethyl)-1H-pyrazole (8.7 g, 27.1 mmol) in THF (75 mL) at 0° C. under argon was added isopropylmagnesium chloride as a 2 M solution in THF (27.1 mL, 54.3 mmol). The reaction was stirred for 1 h at 0° C. To it was added 2-methoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (6.7 mL, 40.7 mmol) and the mixture was stirred for an additional 1 h while allowing to warm to room temperature. It was then treated with saturated ammonium chloride (100 mL) solution and the product was extracted with EtOAc (3×100 mL). The combined organics were washed with brine, dried over sodium sulfate, and filtered. Crude material was concentrated under reduced pressure to afford 7.1 g (81%) of 1-(2-(tetrahydro-2H-pyran-2-yloxy)ethyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole as a clear yellow oil. The material was taken on crude to the next step. MS m/z=323.2 [M+1]+. Calc'd for C16H27BN2O4: 322.2

Provenance & Evidence