2,2'-Bipyridine → 4-Bromo-1-cyclopropyl-1H-pyrazole

HRID 1046262Notes

Reaction equation

HRID 1046262 reaction equation
[Br:1][C:2]1[CH:3]=[N:4][NH:5][CH:6]=1.[CH:7]1(B(O)O)[CH2:9][CH2:8]1.N1C=CC=CC=1C1C=CC=CN=1.C(=O)([O-])[O-].[Na+].[Na+].[NH4+].[Cl-]>ClCCCl.C([O-])(=O)C.[Cu+2].C([O-])(=O)C>[Br:1][C:2]1[CH:3]=[N:4][N:5]([CH:7]2[CH2:9][CH2:8]2)[CH:6]=1

Participants

8

Reactant 5

HCID 14742,2'-BipyridineHCID 10340Sodium Carbonate2×HCID 163754-BromopyrazoleHCID 25517Ammonium ChlorideHCID 2760897Cyclopropylboronic acid2×

Product 1

HCID 521420994-Bromo-1-cyclopropyl-1H-pyrazole

Reagents, catalysts & solvents 2

HCID 8895Cupric acetateCatalystHCID 111,2-DichloroethaneSolvent

Procedure

A mixture of 4-bromo-1H-pyrazole (0.50 g), cyclopropylboronic acid (0.65 g), copper(II) acetate (0.65 g), 2,2′-bipyridine (0.56 g), and sodium carbonate (0.80 g) in 1,2-dichloroethane (15 mL) was stirred at reflux temperature for 4 h. Then another portion of cyclopropylboronic acid (0.65 g) and sodium carbonate (0.80 g) were added and the mixture was further stirred at reflux temperature overnight. After cooling to room temperature, aqueous NH4Cl solution was added and the resulting mixture was extracted with dichloromethane. The combined extracts were dried (Na2SO4) and the solvent was evaporated. The residue was purified by chromatography on silica gel (cyclohexane/ethyl acetate 95:5->80:20) to afford the title compound as a colorless oil. Yield: 0.32 g (48% of theory); Mass spectrum (ESI+): m/z=187/189 (Br) [M+H]+.

Workup

  1. temperatureat reflux temperature for 4 h
  2. stirringthe mixture was further stirred
  3. temperatureat reflux temperature overnight
  4. extractionthe resulting mixture was extracted with dichloromethane
  5. dry with materialThe combined extracts were dried (Na2SO4)
  6. customthe solvent was evaporated
  7. customThe residue was purified by chromatography on silica gel (cyclohexane/ethyl acetate 95:5->80:20)

Sources & evidence

ORD record
ord-52f26403ea4b45e8a30e0bb15cd8bb22
Source dataset
uspto-grants-2013_10
Patent number
US08569292B2

Reaction notes

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