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

HRID 1967919Notes

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-b7ceb919326744868677c0c6fad99aab
Source dataset: uspto-grants-2013_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08420650B2

Reaction notes

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