Ethyl bromoacetate → tert-Butyl 4-(2-ethoxy-2-oxoethyl)piperazine-1-carboxylate

HRID 1433142Notes

Reaction equation

[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][NH:11][CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].C(=O)([O-])[O-].[Cs+].[Cs+].Br[CH2:21][C:22]([O:24][CH2:25][CH3:26])=[O:23]>>[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][N:11]([CH2:21][C:22]([O:24][CH2:25][CH3:26])=[O:23])[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

Reactant 3

HCID 7748Ethyl bromoacetate

HCID 10796Cesium carbonate

HCID 143452tert-Butyl piperazine-1-carboxylate

Product 1

HCID 22321826tert-Butyl 4-(2-ethoxy-2-oxoethyl)piperazine-1-carboxylateYield 68.2%

Procedure

Piperazine-1-carboxylic acid tert-butyl ester (2.62 g, 14 mmol), cesium carbonate (5 g, 15 mmol) and ethyl bromoacetate (1.56 ml, 14 mmol) was stirred at room temperature for 1 h. The mixture was partitioned between water (200 ml) and diethyl ether (2×100 ml). The combined organic phases were dried over magnesium sulphate and concentrated to give a yellow oil which crystallised to give 4-ethoxycarbonylmethyl-piperazine-1-carboxylic acid tert-butyl ester as a pale yellow solid (2.6 g)

Workup

customThe mixture was partitioned between water (200 ml) and diethyl ether (2×100 ml)
dry with materialThe combined organic phases were dried over magnesium sulphate
concentrationconcentrated
customto give a yellow oil which
customcrystallised

Sources & evidence

ORD record: ord-1c2b567b3df344e1afd591201709d5ae
Source dataset: uspto-grants-2009_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07612201B2

Reaction notes

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