Boron tribromide → 2-(9H-Carbazol-9-yl)-4-methylphenol

Participants

Reaction Steps

A 1.0 M boron tribromide solution in dichloromethane (90 mL, 90 mmol, 1.9 equiv) was added dropwise at −78° C., over 30 minutes, to a solution of compound 4 (13.5 g, 46.98 mmol, 1 equiv) in anhydrous dichloromethane (400 mL). The reaction was warmed to room temperature, when liquid chromatography-mass spectrometry (LCMS) indicated that the reaction was complete. The reaction was quenched with ice-water (200 mL). The layers were separated and the aqueous phase was extracted with dichloromethane (2×100 mL). The combined organic layers were dried over sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified on an ANALOGIX 40-150 g column, eluting with a gradient of 0 to 20% ethyl acetate in heptanes to give compound 5 (12.3 g, 95% yield) as a yellow oil.

Provenance & Evidence