Potassium Carbonate → Tert-butyl 4-(cyclopropanecarbonyl)piperazine-1-carboxylate

HRID 907801Notes

Reaction equation

[N:1]1([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])[CH2:6][CH2:5][NH:4][CH2:3][CH2:2]1.C(=O)([O-])[O-].[K+].[K+].[CH:20]1([C:23](Cl)=[O:24])[CH2:22][CH2:21]1>ClCCl>[CH:20]1([C:23]([N:4]2[CH2:5][CH2:6][N:1]([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])[CH2:2][CH2:3]2)=[O:24])[CH2:22][CH2:21]1

Participants

Conditions

Temperature: 0 °C

Procedure

A mixture of compound tert-butyl piperazine-1 carboxylate (3.725 g, 20 mmol) and potassium carbonate (5.53 g, 40 mmol) in anhydrous dichloromethane (30 mL) was cooled to 0° C., cyclopropanecarbonyl chloride (2.30 g, 22 mmol) was then added dropwise. After the addition, the mixture was stirred at room temperature overnight. The mixture was diluted with dichloromethane (100 mL), washed with 10% citric acid (50 mL), followed by saturated sodium bicarbonate (50 mL), brine (100 mL), dried over anhydrous sodium sulfate, and concentrated to give tert-butyl 4-(cyclopropanecarbonyl)piperazine-1-carboxylate (3.7 g, yield 73%) as a white solid. 1H-NMR (400 MHz, CDCl3) δ (ppm): 0.76-0.81 (m, 2H), 0.98-1.03 (m, 2H), 1.49 (s, 9H), 1.69-1.75 (m, 1H), 3.46-3.48 (m, 4H), 3.63-3.65 (m, 4H); LC-MS (ESI) m/z: 255(M+1)+.

Workup

additionAfter the addition
washwashed with 10% citric acid (50 mL)
dry with materialdried over anhydrous sodium sulfate
concentrationconcentrated

Sources & evidence

ORD record: ord-5cfaa3b18f0a43639c48ddd4cf9f14f6
Source dataset: uspto-grants-2011_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08012976B2

Reaction notes

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