Ethyl Acetate → Tert-butyl 4-(6-bromopyridin-3-yl)piperazine-1-carboxylate

HRID 1640415Notes

Reaction equation

[Br:1]N1C(=O)CCC1=O.[N:9]1[CH:14]=[CH:13][CH:12]=[C:11]([N:15]2[CH2:20][CH2:19][N:18]([C:21]([O:23][C:24]([CH3:27])([CH3:26])[CH3:25])=[O:22])[CH2:17][CH2:16]2)[CH:10]=1.[OH-].[Na+].C(OCC)(=O)C>C(#N)C>[Br:1][C:14]1[N:9]=[CH:10][C:11]([N:15]2[CH2:20][CH2:19][N:18]([C:21]([O:23][C:24]([CH3:27])([CH3:26])[CH3:25])=[O:22])[CH2:17][CH2:16]2)=[CH:12][CH:13]=1

Participants

Conditions

Temperature: 0 °C

Procedure

2.70 g (15.19 mmol) of N-bromosuccinimide (NBS) are added portionwise to a solution of 4 g (15.19 mmol) of 1,1-dimethylethyl 4-(3-pyridyl)-1-piperazinecarboxylate, obtained in step 7.1, in 50 ml of acetonitrile, cooled to about 0° C. Stirring is continued at 0° C. for 15 minutes and then at room temperature for 2 hours. 100 ml of aqueous sodium hydroxide solution (1M) and 100 ml of ethyl acetate are added to the reaction medium. The aqueous phase is separated out and extracted twice with ethyl acetate, the combined organic phases are washed with saturated aqueous sodium chloride solution and dried over sodium sulfate, and the filtrate is concentrated under reduced pressure. 5.16 g of product are thus obtained in the form of an orange-yellow solid, and are used without further purification in the following step.

Workup

waitat room temperature for 2 hours
customThe aqueous phase is separated out
extractionextracted twice with ethyl acetate
washthe combined organic phases are washed with saturated aqueous sodium chloride solution
dry with materialdried over sodium sulfate
concentrationthe filtrate is concentrated under reduced pressure

Sources & evidence

ORD record: ord-b5bb44e21e1e412cb960d7c833d6d8e7
Source dataset: uspto-grants-2012_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08114866B2

Reaction notes

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