Benzyl chloroformate → N-4-Boc-N-1-Cbz-2-piperazine carboxylic acid

HRID 466874Notes

Reaction equation

[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][NH:11][CH:10]([C:14]([OH:16])=[O:15])[CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].Cl[C:18]([O:20][CH2:21][C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1)=[O:19]>[OH-].[Na+]>[CH2:21]([O:20][C:18]([N:11]1[CH2:12][CH2:13][N:8]([C:6]([O:5][C:1]([CH3:4])([CH3:2])[CH3:3])=[O:7])[CH2:9][CH:10]1[C:14]([OH:16])=[O:15])=[O:19])[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1

Participants

Conditions

Temperature: 0 °C

Procedure

0.1 g of 4-(tert.butoxycarbonyl)-piperazine-2-carboxylic acid was dissolved in 10 ml of 1N sodium hydroxide solution, cooled to 0° C. and treated with 0.2 g of benzyl chloroformate. The mixture was allowed to warm to room temperature and was then stirred overnight. The mixture was extracted with diethyl ether. The aqueous phase was then acidified to pH 4 with 2M hydrochloric acid and extracted with ethyl acetate to give 0.06 g of 1-(benzyloxycarbonyl)-4-(tert.butoxycarbonyl)-2-piperazinecarboxylic acid as a white solid; MS: m/e 365 [M+H]+.

Workup

temperatureto warm to room temperature
extractionThe mixture was extracted with diethyl ether
extractionextracted with ethyl acetate

Sources & evidence

ORD record: ord-121842e20f2a43e884fb7e53da548441
Source dataset: uspto-grants-1992_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05157041

Reaction notes

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