Boron tribromide → Ammonia

Participants

Reaction Steps

Boron tribromide (1M in dichloromethane, 1.2 mL, 1.224 mmol) was added to an ice-cooled solution of the product of example 73 (150 mg, 0.306 mmol) in dichloromethane (4 mL) and the mixture was stirred at room temperature for 18 hours. The reaction was quenched with 0.88 ammonia solution and stirred at room temperature for 2 hours. The reaction mixture was adjusted to pH 8 by dropwise addition of 2N hydrochloric acid (aq) and extracted with dichloromethane (3×10 mL). The combined organic layers were dried over sodium sulfate and concentrated in vacuo. Purification of the residue by column chromatography on silica gel, eluting with dichloromethane:methanol:0.88 ammonia, 95:5:0.5, afforded the title compound as a pale brown foam in 49% yield, 71 mg.

Provenance & Evidence