Pyridine → N-(5-bromo-pyridin-2-yl)-3-cyclopentyl-2(R)-(3,4-dichloro-phenyl)-propionamide

Participants

Reaction Conditions

Reaction Steps

A solution of triphenylphosphine (411 mg, 1.57 mmol) in methylene chloride (15 mL) was cooled to 0° C. and then treated with N-bromosuccinimide (316 mg, 1.78 mmol). The reaction mixture was stirred at 0° C. until it was completely dissolved and became light purple in color. The reaction mixture was then treated with 3-cyclopentyl-2(R)-(3,4-dichloro-phenyl)-propionic acid (prepared as in Example 54A, 300 mg, 1.05 mmol). The reaction mixture was stirred at 0° C. for 20 min and then warmed to 25° C. where it was stirred for 30 min. After such time, the reaction mixture was treated with 2-amino-5-bromopyridine (271 mg, 1.57 mmol) and pyridine (0.15 mL, 1.88 mmol). The resulting reaction mixture was stirred at 25° C. for 16 h. The reaction was then diluted with water (10 mL) and extracted with methylene chloride (3×15 mL). The combined organic layers were dried over sodium sulfate, filtered, and concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230-400 mesh, 90/10 hexanes/ethyl acetate) afforded N-(5-bromo-pyridin-2-yl)-3-cyclopentyl-2(R)-(3,4-dichloro-phenyl)-propionamide (448 mg, 97%) as a white solid: mp 107.3-109.9° C.; [α]23589=−66.7° (c=0.084, chloroform); EI-HRMS m/e calcd for C19H19BrCl2N2O (M+) 440.0058, found 440.0056.

Provenance & Evidence