Methylboronic Acid → 4-(3,5,6-Trimethylpyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester

HRID 1804120Notes

Reaction equation

HRID 1804120 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][N:11]([C:14]2C(Cl)=CC(Cl)=C(Cl)[N:15]=2)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].C1(P(C2CCCCC2)C2C=CC=C[C:31]=2[C:36]2[C:41](OC)=[CH:40][CH:39]=[CH:38][C:37]=2OC)CCCCC1.[F-].[K+].CB(O)O>[Cl-].[Na+].O.C([O-])(=O)C.[Pd+2].C([O-])(=O)C.C(OCC)(=O)C.O1CCCC1>[C:1]([O:5][C:6]([N:8]1[CH2:9][CH2:10][N:11]([C:14]2[C:38]([CH3:39])=[CH:37][C:36]([CH3:31])=[C:41]([CH3:40])[N:15]=2)[CH2:12][CH2:13]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

9

Reactant 4

HCID 139377Methylboronic AcidHCID 522689Potassium FluorideHCID 112698722-Dicyclohexylphosphino-2',6'-dimethoxybiphenylHCID 866587754-(3,5,6-Trichloropyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester

Product 1

HCID 673809814-(3,5,6-Trimethylpyridin-2-yl)piperazine-1-carboxylic acid tert-butyl esterYield 306%

Reagents, catalysts & solvents 4

HCID 167845palladium(II) acetateCatalystHCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolventHCID 57417360Sodium chloride; waterSolvent

Procedure

To a mixture of 4-(3,5,6-trichloropyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (9.27 g) described in Preparation Example 173, palladium (II) acetate (851 mg), 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (3.11 g), potassium fluoride (17.6 g) and methylboronic acid (9.08 g) was added tetrahydrofuran (190 mL), and the mixture was refluxed for 5.5 hr. After cooling, to the reaction mixture were added ethyl acetate and saturated brine and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, and dried over sodium sulfate. The solvent was evaporated under reduced pressure and the residue was purified by column chromatography (hexane:ethyl acetate) to give the title compound (7.08 g).

Workup

  1. temperaturethe mixture was refluxed for 5.5 hr
  2. temperatureAfter cooling, to the reaction mixture
  3. extractionthe mixture was extracted with ethyl acetate
  4. washThe organic layer was washed with saturated brine
  5. dry with materialdried over sodium sulfate
  6. customThe solvent was evaporated under reduced pressure
  7. customthe residue was purified by column chromatography (hexane:ethyl acetate)

Sources & evidence

ORD record
ord-95d28118eff74dcdb61b0292b103e3dd
Source dataset
uspto-grants-2013_01
Patent number
US08354401B2

Reaction notes

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