Potassium Carbonate → 1-(Tert-butoxycarbonyl)-4-(3,4-dichlorobenzyl)piperidine

Participants

Reaction Steps

1-Boc-4-methylene piperidine (1.32 g, 6.70 mmol) was degassed (neat) for 15 minutes, and then treated with a THF solution of 9-BBN (0.5 M in THF, 13.5 mL, 6.75 mmol). The reaction mixture was refluxed for 2 h, then cooled to r.t. The reaction mixture was then added, via cannula, to a preformed solution consisting of 4-bromo-1,2-dichlorobenzene (1.49 mg, 6.64 mmol), Pd(dppf)Cl2 dichloromethane complex (148 mg, 0.181 mmol), and potassium carbonate (1.20 g, 8.68 mmol) in DMF/H2O (15 mL/1.5 mL). The resultant mixture was heated at 60° C. for 48 h, cooled to r.t., poured into water, basified to pH 11 with 1N NaOH, and extracted with EtOAc (3×). The organic layers were combined, dried (Na2SO4), and concentrated. The crude residue was purified (FCC) to give 4-(3,4-dichloro-benzyl)-piperidine-1-carboxylic acid tert-butyl ester (1.57 g, 69%).

Provenance & Evidence