Triphenylphosphine → N-(5-bromo-pyridin-2-yl)-2-(4-chloro-3-nitro-phenyl)-3-cyclopentyl-propionamide

Participants

Reaction Conditions

Reaction Steps

A solution of triphenylphosphine (241 mg, 0.92 mmol) in methylene chloride (3 mL) was cooled to 0° C. and then slowly treated with N-bromosuccinimide (164 mg, 0.92 mmol). The reaction mixture was stirred at 0° C. for 10 min and then treated with 2-(4-chloro-3-nitro-phenyl)-3-cyclopentyl-propionic acid (prepared as in Example 64, 250 mg, 0.84 mmol). The resulting reaction mixture was stirred at 0° C. for 5 min and then allowed to warm to 25° C. where it was stirred for 30 min. The reaction mixture was then treated with 2-amino-5-bromopyridine (320 mg, 1.85 mmol). The crude reaction mixture was then directly purified by flash chromatography (Merck Silica gel 60, 230-400 mesh, 3/1 hexanes/ethyl acetate) to afford N-(5-bromo-pyridin-2-yl)-2-(4-chloro-3-nitro-phenyl)-3-cyclopentyl-propionamide (216 mg, 57%) as a pale yellow solid: mp 128-130° C.; EI-HRMS m/e calcd for C19H19BrClN3O3 (M+) 451.0298, found 451.0300.

Provenance & Evidence