反应详情

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).

1. stirringThe reaction mixture was stirred for 10 mins
2. customafter which time the solvent was removed under reduced pressure
3. additionthe residue diluted with ethyl acetate and water
4. customThe organic layer was separated
5. dry with materialdried over magnesium sulphate
6. customthe solvent was removed under reduced pressure