Carbon tetrabromide → tert-Butyl 4-(2-bromoethyl)piperidine-1-carboxylate

Participants

Reaction Steps

A mixture of 4-(2-hydroxy-ethyl)-piperidine-1-carboxylic acid tert-butyl ester (94.0 Og 0.41 mol), carbon tetrabromide (198.7 g 0.6 mol) and dichloromethane (1500 ml) at 0° under nitrogen was treated portionwise, over 45 min, with triphenylphosphine (135.2 g 0.515 mol). The mixture was stirred for 1 h at 10° and 1 h at 25° and then evaporated in vacuo. The residue was purified by flash column chromatography on silica gel (Merck 9385), eluant cyclohexane: ethyl acetate (15:1, gradient to 10:1) to give the title compound as a clear liquid (81.8 g, 0.28 mol, 68%).

Provenance & Evidence