Methanol → HCID 86596808, compound

Participants

Reaction Steps

To a solution of 4-(4-bromo-phenyl)-4-cyano-piperidine-1-carboxylic acid tert-butyl ester from Step 2 (5.67 g, 15.57 mmol, 1 eq) in 60 mL of dichloromethane was add a solution of DIBAL-H (1M in toluene, 23.36 mL, 23.36 mmol, 1.5 eq) in a drop-wise fashion. The resulting mixture was stirred at room temperature for 20 h and then 15 mL of methanol was added carefully. The mixture was stirred for 0.25 h and a precipitate formed. The resulting mixture was filtered through Celite and the salts were washed several times with ethyl acetate. The filtrate was adsorbed onto silica gel and purified by flash column chromatography eluting with a gradient of 5-20% ethyl acetate in hexane to give 1.78 g of 4-(4-bromo-phenyl)-4-(2-oxo-ethyl)-piperidine-1-carboxylic acid tert-butyl ester and 1.54 g of recovered starting material. 1H NMR (300 MHz, CDCl3): δ 9.35 (s, 1H), 7.50-7.46 (d, 2H), 7.15-7.10 (d, 2H), 3.82 (br. s, 2H), 3.11-3.04 (t, 2H), 2.35-2.28 (dt, 2H), 1.90 (br. s, 2H), 1.42 (s, 9H).

Provenance & Evidence