N-bromobutanimide → Tert-butyl 4-(5-bromo-3-chloropyrazin-2-yl)piperazine-1-carboxylate

HRID 1045707Notes

Reaction equation

[Cl:1][C:2]1[C:3]([N:8]2[CH2:13][CH2:12][N:11]([C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[CH2:10][CH2:9]2)=[N:4][CH:5]=[CH:6][N:7]=1.[Br:21]N1C(=O)CCC1=O>C(Cl)(Cl)Cl>[Br:21][C:6]1[N:7]=[C:2]([Cl:1])[C:3]([N:8]2[CH2:9][CH2:10][N:11]([C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[CH2:12][CH2:13]2)=[N:4][CH:5]=1

Participants

Conditions

Temperature: 20 °C

Procedure

A 500 mL round bottom flask was charged with tert-butyl 4-(3-chloropyrazin-2-yl)piperazine-1-carboxylate (13.5 g, 45.3 mmol), N-bromosuccinimide (10.48 g, 58.9 mmol) and CHCl3 (150 mL). The resulting mixture was stirred at 20° C. overnight and it became a clear solution. The solvent was evaporated and the residue was purified by flash column chromatography on silica gel with 0-10% EtOAc in petroleum ether, to afford 16.1 g (94%) of the product as a white solid. 1H NMR (300 MHz, CDCl3) δ: 8.18 (s, 1H), 3.57 (m, 4H), 3.39 (m, 4H), 1.48 (s, 9H).

Workup

customThe solvent was evaporated
customthe residue was purified by flash column chromatography on silica gel with 0-10% EtOAc in petroleum ether

Sources & evidence

ORD record: ord-339e0aed389a4042a71d32fb856ff4c1
Source dataset: uspto-grants-2013_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08569300B2

Reaction notes

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