Ammonium Chloride → HCID 66582880, compound

HRID 1972634Notes

Reaction equation

[O:1]=[C:2]1[CH2:7][N:6]([C:8]([O:10][CH2:11][C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)=[O:9])[CH2:5][CH2:4][N:3]1[C:18]([O:20][C:21]([CH3:24])([CH3:23])[CH3:22])=[O:19].[C:25]([Mg]Br)#[C:26][CH3:27].[NH4+].[Cl-]>C1COCC1>[C:21]([O:20][C:18]([NH:3][CH2:4][CH2:5][N:6]([CH2:7][C:2](=[O:1])[C:25]#[C:26][CH3:27])[C:8](=[O:9])[O:10][CH2:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)=[O:19])([CH3:24])([CH3:23])[CH3:22]

Participants

Conditions

Temperature: 0 °C

Procedure

A 150-mL round-bottomed flask was charged with 4-benzyl 1-tert-butyl 2-oxo-1,4-piperazinedicarboxylate (1.41 g, 4.22 mmol) and THF (5 mL). 1-Propynylmagnesium bromide (0.5 M in THF, 20.0 mL, 10.0 mmol, Sigma-Aldrich, St. Louis, Mo.) was added at 0° C. slowly. The mixture was stirred at 0° C. for 2 h. Saturated aqueous NH4Cl (40 mL) was added and the aqueous phase was extracted with EtOAc (200 mL, then 2×100 mL). The combined organic phases were dried over sodium sulfate, filtered and concentrated in vacuo. The crude product was purified by column chromatography (50 g of silica, 0 to 50% EtOAc in hexanes) to afford benzyl (2-((tert-butoxycarbonyl)amino)ethyl)(2-oxo-3-pentyn-1-yl)carbamate (1.55 g) as a clear oil.

Workup

extractionthe aqueous phase was extracted with EtOAc (200 mL
dry with materialThe combined organic phases were dried over sodium sulfate
filtrationfiltered
concentrationconcentrated in vacuo
customThe crude product was purified by column chromatography (50 g of silica, 0 to 50% EtOAc in hexanes)

Sources & evidence

ORD record: ord-92750f86e4084d6d8fa52ee9747e5c05
Source dataset: uspto-grants-2013_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08431563B2

Reaction notes

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