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

HRID 222047Notes

Reaction equation

O=[C:2]1[CH2:7][CH2:6][N:5]([C:8]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9])[CH2:4][CH2:3]1.[C:15]([O:19][C:20]([CH3:23])([CH3:22])[CH3:21])(=[O:18])[NH:16][NH2:17]>C1(C)C=CC=CC=1>[C:20]([O:19][C:15]([NH:16][N:17]=[C:2]1[CH2:7][CH2:6][N:5]([C:8]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9])[CH2:4][CH2:3]1)=[O:18])([CH3:23])([CH3:22])[CH3:21]

Participants

Conditions

Temperature: 70 °C

Procedure

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.

Workup

customPrecipitate was formed
temperatureupon cooling down to rt
filtrationFiltration of the heterogeneous mixture

Sources & evidence

ORD record: ord-f17d32207e6f4a72acb965a24af1c33e
Source dataset: uspto-grants-2012_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08207172B2

Reaction notes

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