2-Chloromethyl 2-(trimethylsilyl)ethyl ether → 4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-pyrazole

Participants

Reaction Steps

To a solution of 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (8.2 g, 41 mmol) in NMP (60 mL) was added K2 CO3 (12 g, 82 mmol) and 2-(trimethylsilyl)ethoxymethyl chloride (7.8 mL, 43 mmol) in sequence. The reaction mixture was stirred at r.t. under N2 for 16 h. Then, the reaction mixture was diluted and filtered, and then the filtrate was diluted with EtOAc (300 mL). The resulting solution was washed with sat. NaHCO3 (aq) (3×200 mL), H2O (4×200 mL), brine (1×200 mL), dried over Na2SO4, filtered, concentrated and dried in vacuo to yield intermediate Int-15a (11.4 g, 86%) as a clear yellowish oil.

Provenance & Evidence