Toluene → 4-(5-Cyclopropyl-3-methylpyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester

HRID 1803986Notes

Reaction equation

HRID 1803986 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][N:11]([C:14]2[C:19]([CH3:20])=[CH:18][C:17](Br)=[CH:16][N:15]=2)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].P([O-])([O-])([O-])=O.[K+].[K+].[K+].[CH:30]1(B(O)O)[CH2:32][CH2:31]1.C1(C)C=CC=CC=1>C1CCC(P(C2CCCCC2)C2CCCCC2)CC1.C1CCC(P(C2CCCCC2)C2CCCCC2)CC1.[Cl-].[Cl-].[Pd+2].O>[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][N:11]([C:14]2[C:19]([CH3:20])=[CH:18][C:17]([CH:30]3[CH2:32][CH2:31]3)=[CH:16][N:15]=2)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

7

Reactant 4

HCID 1140TolueneHCID 62657Potassium Phosphate, TribasicHCID 2760897Cyclopropylboronic acidHCID 46739269tert-Butyl 4-(5-bromo-3-methylpyridin-2-yl)piperazine-1-carboxylate

Product 1

HCID 673810094-(5-Cyclopropyl-3-methylpyridin-2-yl)piperazine-1-carboxylic acid tert-butyl esterYield 68.6%

Reagents, catalysts & solvents 2

HCID 11556747Bis(tricyclohexylphosphine)palladium(II) DichlorideCatalystHCID 962WaterSolvent

Procedure

To a mixture of 4-(5-bromo-3-methylpyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (3.6 g), bis(tricyclohexylphosphine)palladium (II) dichloride (396 mg), tripotassium phosphate (12 g) and cyclopropylboronic acid (2.1 g) were added toluene (30 mL) and water (1.5 mL), and the mixture was refluxed for 8 hr. After cooling, the mixture was extracted with ethyl acetate, washed with saturated brine, and the solvent was evaporated. The residue was purified by column chromatography (chloroform) to give 4-(5-cyclopropyl-3-methylpyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (2.2 g). 4-(5-Cyclopropyl-3-methylpyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (2.2 g) was dissolved in chloroform (5 mL), 4N hydrogen chloride/ethyl acetate (5 mL) was added, and the mixture was stirred at room temperature overnight. Ethyl acetate (20 mL) was added, and the mixture was filtered to give the title compound (1.3 g).

Workup

  1. temperaturethe mixture was refluxed for 8 hr
  2. temperatureAfter cooling
  3. extractionthe mixture was extracted with ethyl acetate
  4. washwashed with saturated brine
  5. customthe solvent was evaporated
  6. customThe residue was purified by column chromatography (chloroform)

Sources & evidence

ORD record
ord-b811dfefbc9c4d9bae84f528c969b907
Source dataset
uspto-grants-2013_01
Patent number
US08354401B2

Reaction notes

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