Phenacyl bromide → (3R)-3-(2-(tert-butoxycarbonylamino)-2-(4-chlorophenyl)acetoxy)-1-(2-oxo-2-phenylethyl)-1-azoniabicyclo[2.2.2]octane bromide

Participants

Reaction Steps

2-Bromo-1-phenylethanone (55.4 mg, 0.28 mmol) was added to a solution of (R)-quinuclidin-3-yl 2-(tert-butoxycarbonylamino)-2-(4-chlorophenyl)acetate (C47) (100 mg, 0.25 mmol) in EtOAc (3 ml). The reaction was stirred at RT for 36 hours, and then a second portion of 2-bromo-1-phenylethanone (50.4 mg, 0.25 mmol) was added, and the reaction was stirred at RT for additional 48 hours. The organic phase was washed with aq. Na2CO3, dried over Na2SO4 and evaporated. The crude was dissolved in acetonitrile (3 ml), and 2-bromo-1-phenylethanone (60.0 mg, 0.30 mmol) was added. The reaction was heated under microwave irradiation at 100° C. for 45 minutes. The solvent was evaporated and the crude was purified by flash chromatography (DCM/MeOH=95/5 to 9/1) to obtain (3R)-3-(2-(tert-butoxycarbonylamino)-2-(4-chlorophenyl)acetoxy)-1-(2-oxo-2-phenylethyl)-1-azoniabicyclo[2.2.2]octane bromide (62.5 mg; 42% yield).

Provenance & Evidence