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

HRID 1467539Notes

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-0bd281d98b5d4c0fa42453d342c94b10
Source dataset: uspto-grants-2015_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08999987B2

Reaction notes

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