Bromoacetyl bromide → tert-Butyl 4-[2-bromo-N-[4-(trifluoromethyl)phenyl]acetamido]piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

A solution of the product of Example 166A (480 mg, 1.39 mmol) and N-ethyl-N-isopropylpropan-2-amine (0.486 mL, 2.79 mmol) in anhydrous tetrahydrofuran (10 mL) was cooled in an ice water bath for 10 minutes followed by the dropwise addition of bromoacetyl bromide (0.146 mL, 1.67 mmol) via syringe. The reaction was stirred for 30 minutes at 0° C., then 1 hour at ambient temperature and 3 hours at reflux. The reaction mixture was cooled to ambient temperature and diluted with ethyl acetate. The organic solution was washed with 1 N aqueous HCl and saturated NaHCO3 solution and brine, dried with Na2SO4, filtered, and concentrated in vacuo. The crude product was chromatographed on silica gel (Analogix® Intelliflash™ 280; SF25-60 g column; 50% ethyl acetate/hexanes) which yielded the title compound. 1H NMR (300 MHz, CDCl3) δ ppm 7.74 (d, J=8.4, 2H), 7.34 (d, J=8.2, 2H), 4.80-4.66 (m, 1H), 4.25-4.04 (m, 2H), 3.49 (s, 2H), 2.79 (t, J=12.4, 2H), 1.87-1.77 (m, 2H), 1.39 (s, 9H), 1.29-1.11 (m, 2H); MS (DCI+) m/z 482/484 (M+NH4)+.

Provenance & Evidence