反应详情

0.278 g (0.00127 mol) of 1-benzylpiperidine-4-carboxylic acid was boiled at reflux in 5 ml of oxalyl chloride for 2 hrs. The excess oxalyl chloride was distilled off. The residue was taken up twice in toluene and concentrated each time. 0.3 g (99%) of 1-benzylpiperidine-4-carboxylic acid chloride was obtained as a pale beige solid. This was dissolved in 20 ml of toluene, treated with 0.265 ml (0.0019 mol) of triethylamine and 0.17 g (0.00165 mol) of benzyl alcohol and boiled at reflux for 18 hrs. After removal of the solvent the residue was chromatographed on silica gel with ether/hexane (1:2) as the eluent. 0.246 g (80%) of benzyl 1-benzylpiperidin-4-carboxylate was obtained as a yellow oil. MS: me/e=310 (C2H23NO2+).

1. distillationThe excess oxalyl chloride was distilled off
2. concentrationconcentrated each time