Bromine → 4-(4-bromo-1-methyl-1H-pyrazol-5-yl)pyridine

HRID 1726388Notes

Reaction equation

HRID 1726388 reaction equation
[CH3:1][N:2]1[C:6]([C:7]2[CH:12]=[CH:11][N:10]=[CH:9][CH:8]=2)=[CH:5][CH:4]=[N:3]1.CN1C=CC(C2C=CN=CC=2)=N1.[Br:25]Br.C(=O)(O)[O-].[Na+]>C(Cl)(Cl)Cl.ClCCl>[Br:25][C:5]1[CH:4]=[N:3][N:2]([CH3:1])[C:6]=1[C:7]1[CH:12]=[CH:11][N:10]=[CH:9][CH:8]=1

Participants

7

Reactant 4

HCID 24408BromineHCID 516892Sodium BicarbonateHCID 200610284-(1-methyl-1H-pyrazol-3-yl)pyridineHCID 569561404-(1-methyl-1H-pyrazol-5-yl)pyridine

Product 1

HCID 689272584-(4-bromo-1-methyl-1H-pyrazol-5-yl)pyridineYield 73%

Reagents, catalysts & solvents 2

HCID 6212ChloroformSolvent2×HCID 6344DichloromethaneSolvent

Procedure

To a 3.8:1 isomer mix of 4-(1-methyl-1H-pyrazole-5-yl)pyridine and 4-(1-methyl-1-H-pyrazole-3-yl)pyridine (0.30 g) in 5 mL chloroform cooled in ice, was added a solution of 104 μL bromine in 3 mL chloroform. After 5 h, the mixture was treated with excess saturated aqueous sodium bicarbonate and diluted with dichloromethane. The dichloromethane was washed with 3 portions of saturated aqueous sodium bicarbonate, dried over magnesium sulfate, filtered, and evaporated to yield 0.39 g crude product as a brown oil. The crude product was purified by chromatography, eluting with 15:1 ethyl acetate-methanol. Fractions containing the major component were combined to afford 0.17 g (73% yield) of a colorless oil. 1H NMR (CDCl3) was consistent with the desired structure. LC/MS indicated one major product with a M+1 molecular ion of m/z 240.3 by positive ESI.

Workup

  1. temperaturecooled in ice
  2. washThe dichloromethane was washed with 3 portions of saturated aqueous sodium bicarbonate
  3. dry with materialdried over magnesium sulfate
  4. filtrationfiltered
  5. customevaporated
  6. customto yield 0.39 g crude product as a brown oil
  7. customThe crude product was purified by chromatography
  8. washeluting with 15:1 ethyl acetate-methanol
  9. additionFractions containing the major component

Sources & evidence

ORD record
ord-8ce73f2308e44ffbb49d4d97a778d2ac
Source dataset
uspto-grants-2009_02
Patent number
US07491829B2

Reaction notes

Loading…