Ethyl Acetate → 1-(5-Ethyl-3-methylpyridin-2-yl)piperazine hydrochloride

HRID 1804048Notes

Reaction equation

HRID 1804048 reaction equation
C(OC([N:8]1[CH2:13][CH2:12][N:11]([C:14]2[C:19]([CH3:20])=[CH:18][C:17]([CH2:21][CH3:22])=[CH:16][N:15]=2)[CH2:10][CH2:9]1)=O)(C)(C)C.[ClH:23].C(OCC)(=O)C.C(OCC)(=O)C>C(Cl)(Cl)Cl>[ClH:23].[CH2:21]([C:17]1[CH:18]=[C:19]([CH3:20])[C:14]([N:11]2[CH2:10][CH2:9][NH:8][CH2:13][CH2:12]2)=[N:15][CH:16]=1)[CH3:22]

Participants

5

Reactant 3

HCID 8857Ethyl AcetateHCID 21866389Hydrogen chloride-ethyl acetateHCID 673812894-(5-Ethyl-3-methylpyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester

Product 1

HCID 673809241-(5-Ethyl-3-methylpyridin-2-yl)piperazine hydrochloride

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

To a mixture of 4-(5-bromo-3-methylpyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (11 g), bis(tricyclohexylphosphine)palladium (II) dichloride (1 g), tripotassium phosphate (13 g) and vinylboronic acid pinacol ester (10 g) were added toluene (90 mL) and water (4.5 mL), and the mixture was refluxed for 8 hr. After cooling, the mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, and the solvent was evaporated. The residue was purified by column chromatography (hexane:ethyl acetate) to give 4-(3-methyl-5-vinylpyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (9 g). 4-(3-Methyl-5-vinylpyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (9 g) was dissolved in ethanol (90 mL), 5% palladium carbon-ethylenediamine complex (2 g) was added, and the mixture was stirred under a hydrogen atmosphere at room temperature overnight. After celite filtration, the solvent in the filtrate was evaporated to give 4-(5-ethyl-3-methylpyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (9 g). 4-(5-Ethyl-3-methylpyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (9 g) was dissolved in chloroform (20 mL), 4N hydrogen chloride/ethyl acetate (20 mL) was added, and the mixture was stirred at room temperature overnight. Ethyl acetate (100 mL) was added, and the precipitate was collected by filtration to give the title compound (5 g).

Workup

  1. filtrationthe precipitate was collected by filtration

Sources & evidence

ORD record
ord-779bd28a8cce4d5cacea5e5c3c3f804b
Source dataset
uspto-grants-2013_01
Patent number
US08354401B2

Reaction notes

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