Boron tribromide → HCID 86615322, compound

Participants

Reaction Conditions

Reaction Steps

The suspension is filtered through Celite, the filter bed being rinsed thoroughly with ethyl acetate. The phases of the filtrate are separated and extraction is carried out again with ethyl acetate. The extracts are dried over sodium sulphate and the solvent is removed in vacuo to give 205 mg of (2R,4R)-4-(3-fluoro-2-methoxyphenyl)-1-[(7-fluoro-2-methylquinolin-5-yl)imino]-2-(trifluoromethyl)-hexan-2-ol as a crude product. The crude imine is dissolved in 18 ml of CH2Cl2 and the solution is cooled to −40° C. 3.4 ml (3.4 mmol) of a 1 M BBr3 solution in dichloromethane are added slowly dropwise over 5 minutes and the mixture is allowed to warm to 0° C. over 1 hour, and after 30 minutes at 0° C. is poured onto a mixture of saturated NaHCO3 and ice. It is extracted repeatedly with ethyl acetate and the extracts are washed with saturated NaCl solution and dried over Na2SO4. Purification by column chromatography on silica gel (150 ml) with ethyl acetate affords 37 mg of product (analytical HPLC: Rt=9.2 min (Chiralcel OD 5μ, 250×4.6 mm, hexane/ethanol 10%, 1 ml/min flow rate) as the (−)-enantiomer.

Provenance & Evidence