Toluene → 4-(2-Cyclopropyl-4-methylphenyl)piperazine-1carboxylic acid tert-butyl ester

HRID 1803955Notes

Reaction equation

HRID 1803955 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][N:11]([C:14]2[CH:19]=[CH:18][C:17]([CH3:20])=[CH:16][C:15]=2Cl)[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[CH:19]=[CH:18][C:17]([CH3:20])=[CH:16][C:15]=2[CH:30]2[CH2:32][CH2:31]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 673810454-(2-Chloro-4-methylphenyl)piperazine-1-carboxylic acid tert-butyl ester

Product 1

HCID 673807494-(2-Cyclopropyl-4-methylphenyl)piperazine-1carboxylic acid tert-butyl esterYield 105.4%

Reagents, catalysts & solvents 2

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

Procedure

To a mixture of 4-(2-chloro-4-methylphenyl)piperazine-1-carboxylic acid tert-butyl ester (932 mg), bis(tricyclohexylphosphine)palladium (II) dichloride (132 mg), tripotassium phosphate (3.8 g) and cyclopropylboronic acid (688 mg) were added toluene (10 mL) and water (500 μL) and the mixture was refluxed for 5 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-(2-cyclopropyl-4-methylphenyl)piperazine-1carboxylic acid tert-butyl ester (1 g). 4-(2-Cyclopropyl-4-methylphenyl)piperazine-1carboxylic acid tert-butyl ester (1 g) was dissolved in chloroform (1 mL), 4N hydrogen chloride/ethyl acetate (1 mL) was added, and the mixture was stirred at room temperature for 3 hr. Filtration gave 1-(2-cyclopropyl-4-methylphenyl)piperazine hydrochloride (160 mg). To tetrahydrofuran (2 mL) were added 4-iodobenzoyl chloride (169 mg), 1-(2-cyclopropyl-4-methylphenyl)piperazine hydrochloride (160 mg) and 1N aqueous sodium hydroxide solution (2 mL), and the mixture was stirred at room temperature overnight. Ethyl acetate was added for partitioning, the organic layer was washed with saturated brine, and the solvent was evaporated. The residue was purified by column chromatography (chloroform) to give the title compound (280 mg).

Workup

  1. temperaturethe mixture was refluxed for 5 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-ff620357565b47858653b8959aaf7b5e
Source dataset
uspto-grants-2013_01
Patent number
US08354401B2

Reaction notes

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