tert-Butyl carbazate → Tert-butyl 4-[(tert-butoxycarbonyl)hydrazono]piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl 4-oxopiperidine-1-carboxylate (2 g, 10 mmol, 1 eq) in toluene (50 mL) was added tert-butyl carbazate (1.3 g, 10 mmol, 1 eq). The contents were stirred at 70° C. for 17 h. Precipitate was formed upon cooling down to rt. Filtration of the heterogeneous mixture gave a white solid (2.3 g). The filtrate was concentrated to dryness and triturated with ether carefully to collect another crop of solid (400 mg). The two solid product crops were combined (2.7 g, 85%) and used directly in the next step. 1H-NMR (CH3CN-d3) δ 8.11 (s, 1H), 3.49 (m, 4H), 2.34 (m, 4H), 1.47 (s, 9H), 1.45 (s, 9H); LCMS RT=3.04 min; [M+Na]+=336.1.

Provenance & Evidence