tert-Butanol → Benzyl 3-(tert-butoxycarbonylamino)piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

(R)N-CBz nipecotic acid (86 g, 327 mmol) was dissolved in toluene (100 ml) and evaporated to dryness three times. tert. Butanol (1000 ml, 10.5 mmol) and triethylamine (50.1 ml, 359 mmol) were added to the reaction mixture. The reaction mixture was stirred for 30 min., and DPPA (98.5 ml, 457 mmol) was added over 15 min. The reaction mixture was heated to 100° C. overnight. After cooling, the solvent was removed by evaporation in vacuo, and water (200 ml) was added. After overnight stirring at RT the product was isolated by filtration, and stirred with EtOAc (250 ml) for one hour. The EtOAc solution was filtered and evaporated in vacuo to give the crude product as a white solid. This material was dissolved in hot EtOAc (200 ml), and cooled to 5° C. overnight. The precipitated product was isolated by filtration, washed with cold EtOAc and dried.

Provenance & Evidence