Ammonia → (s)-1-n-boc-pipecolamide

Participants

Reaction Steps

Triethylamine (14.46 ml) was added to a solution of (2S)-1-(tert-butoxycarbonyl)-2-piperidinecarboxylic acid (18.3 g) [see Preparation 1] in tetrahydrofuran (240 ml) at −20° C. under an atmosphere of nitrogen. Ethyl chloroformate (7.52 ml) was then added to the mixture and the resulting solution was stirred for 40 mins. at −10° C. and then 0.88 aqueous ammonia solution (32 ml) added. The reaction mixture was stirred for 10 mins. after which time the solvent was removed under reduced pressure and the residue diluted with ethyl acetate and water. The organic layer was separated and dried over magnesium sulphate and the solvent was removed under reduced pressure to afford tert-butyl (2S)-2-(aminocarbonyl)-1-piperidinecarboxylate (18.65 g) as a white solid. 1H-NMR (CDCl3) δ: 6.0 (1H, bs), 5.40 (1H, bs), 4.80 (1H, s), 4.00 (1H, m), 2.85 (1H, t), 2.30 (1H, d), 1.80-1.40 (14H, m).

Provenance & Evidence