Cesium carbonate → 1-Isoamyl-4-(4-bromophenyl)pyrazole

HRID 1850031Notes

Reaction equation

HRID 1850031 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5](I)=[CH:4][CH:3]=1.[CH2:9]([N:14]1[CH:18]=[C:17](B(O)O)[CH:16]=[N:15]1)[CH2:10][CH:11]([CH3:13])[CH3:12].C([O-])(=O)C.[K+].C([O-])([O-])=O.[Cs+].[Cs+]>CS(C)=O.C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.Cl[Pd]Cl.[Fe+2]>[CH2:9]([N:14]1[CH:18]=[C:17]([C:5]2[CH:6]=[CH:7][C:2]([Br:1])=[CH:3][CH:4]=2)[CH:16]=[N:15]1)[CH2:10][CH:11]([CH3:13])[CH3:12]

Participants

7

Reactant 4

HCID 10796Cesium carbonateHCID 115221-Bromo-4-iodobenzeneHCID 517044Potassium AcetateHCID 114239411-(3-Methylbutyl)-1H-pyrazole-4-boronic acid

Product 1

HCID 669156251-Isoamyl-4-(4-bromophenyl)pyrazoleYield 82%

Reagents, catalysts & solvents 2

HCID 178418228Bis(cyclopenta-1,4-dien-1-yl(diphenyl)phosphane);dichloropalladium;iron(2+)CatalystHCID 679Dimethyl SulfoxideSolvent

Procedure

4-Bromoiodobenzene (460 mg, 1.6 mmol, 1.5 eq.), 1-isoamylpyrazole-4-boronic acid (200 mg, 1.1 mmol), potassium acetate (100 mg, 1.0 eq.), Pd(dppf)Cl2 (100 mg, 0.1 eq.), and Cs2CO3 (1 g, 3.0 eq.) in DMSO (5 mL) were heated under argon at 80° C. during 1 h. The reaction mixture was extracted from water into ether, dried Na2SO4, concentrated, and chromatographed on silica gel (0→10% EtOAc/hexanes) to give 1-isoamyl-4-(4-bromophenyl)pyrazole (263 mg, 82%).

Workup

  1. extractionThe reaction mixture was extracted from water into ether, dried Na2SO4
  2. concentrationconcentrated
  3. customchromatographed on silica gel (0→10% EtOAc/hexanes)

Sources & evidence

ORD record
ord-043dcc4d0cee4e3ca52b2a0488872cee
Source dataset
uspto-grants-2015_02
Patent number
US08957049B2

Reaction notes

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