Bromine → 3-Bromo-2-(propan-2-yl)pyrazolo[1,5-a]pyridine

HRID 483084Notes

Reaction equation

HRID 483084 reaction equation
[CH:1]([C:4]1[CH:12]=[C:7]2[CH:8]=[CH:9][CH:10]=[CH:11][N:6]2[N:5]=1)([CH3:3])[CH3:2].[Br:13]Br.S(=O)(O)[O-].[Na+]>C(Cl)(Cl)Cl>[CH:1]([C:4]1[C:12]([Br:13])=[C:7]2[CH:8]=[CH:9][CH:10]=[CH:11][N:6]2[N:5]=1)([CH3:3])[CH3:2]

Participants

5

Reactant 3

HCID 24408BromineHCID 113786582-Isopropylpyrazolo[1,5-a]pyridineHCID 23665763Sodium Bisulfite

Product 1

HCID 133917233-Bromo-2-(propan-2-yl)pyrazolo[1,5-a]pyridine

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

To a solution of 50 g of 2-isopropylpyrazolo[1,5-a]pyridine in 300 ml of chloroform were added about 20 ml of bromine until the solution became faintly yellow under stirring and cooling to 5°-15° C. After the addition was completed, the mixture was stirred at room temperature for 30 minutes, then poured into aqueous 10% sodium bisulfite solution and extracted with chloroform. The chloroform layer was washed with aqueous 10% sodium hydroxide and then water, dried over anhydrous sodium sulfate, and concentrated in vacuo to give 75 g of crude 2-isopropyl-3-bromopyrazolo[1,5-a]pyridine, as colorless needles, mp 51°-52° C.

Workup

  1. temperaturecooling to 5°-15° C
  2. additionAfter the addition
  3. stirringthe mixture was stirred at room temperature for 30 minutes
  4. extractionextracted with chloroform
  5. washThe chloroform layer was washed with aqueous 10% sodium hydroxide
  6. dry with materialwater, dried over anhydrous sodium sulfate
  7. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-36ff9a1d0ec4424ca942461890ea3d39
Source dataset
uspto-grants-1986_03
Patent number
US04578392

Reaction notes

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