Trimethyl borate → Dimethyl[5-(benzyloxy)-1-(biphenyl-3-yl)-4-oxo-1,4-dihydropyridin-3-yl]boronate

Participants

Reaction Steps

Lithium chloride (515 mg, 12.1 mmol) in a 25 mL round bottom flask under high vacuum was heated with a heat gun until a free flowing granular solid was obtained (˜5 min). The flask was cooled to room temperature, purged with N2, and treated with isopropylmagnesium chloride (6.1 mL of a 2 M solution in THF). After stirring at room temperature for 1 h, the mixture was cooled to −10° C. and treated with 3-(benzyloxy)-1-(biphenyl-3-yl)-5-bromopyridin-4(1H)-one (1.05 g, 2.4 mmol) as a suspension in 3.5 mL of THF. After stirring for 0.5 h, trimethylborate (1.35 mL, 12.1 mmol) was added drop wise and the reaction mixture was stirred an additional 3.5 h, before being quenched with the addition of MeOH (12 mL) to provide a solution of crude dimethyl[5-(benzyloxy)-1-(biphenyl-3-yl)-4-oxo-1,4-dihydropyridin-3-yl]boronate which was used directly in the subsequent step. LC/S (M+H)+ 398.

Provenance & Evidence