Boron tribromide → 1-(4-hydroxyphenyl)-1H-pyrazole-4-carbonitrile

HRID 1520908Notes

Reaction equation

HRID 1520908 reaction equation
C[O:2][C:3]1[CH:8]=[CH:7][C:6]([N:9]2[CH:13]=[C:12]([C:14]#[N:15])[CH:11]=[N:10]2)=[CH:5][CH:4]=1.B(Br)(Br)Br>ClCCl>[OH:2][C:3]1[CH:4]=[CH:5][C:6]([N:9]2[CH:13]=[C:12]([C:14]#[N:15])[CH:11]=[N:10]2)=[CH:7][CH:8]=1

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 533021171-(4-methoxyphenyl)-1H-pyrazole-4-carbonitrile

Product 1

HCID 671200531-(4-hydroxyphenyl)-1H-pyrazole-4-carbonitrileYield 43.2%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 1-(4-methoxyphenyl)-1H-pyrazole-4-carbonitrile (115 mg, 0.575 mmol) in dichloromethane (5 mL) was added boron tribromide (431 mg, 1.73 mmol) at −10° C. The reaction was then warmed to room temperature and stirred for 16 hours. The reaction was quenched with methanol (0.5 mL) and water (5 mL), and extracted with ethyl acetate (3×15 mL). The combined organics were washed with brine (15 mL), dried over sodium sulfate, filtered and concentrated to give 1-(4-hydroxyphenyl)-1H-pyrazole-4-carbonitrile (46 mg, 43%) as a yellow solid. 1H NMR (400 MHz, CDCl3, δ): 9.89 (s, 1H), 9.12 (s, 1H), 8.27 (s, 1H), 7.62 (d, J=9.2 Hz, 2H), 6.90 (d, J=9.2 Hz, 2H).

Workup

  1. customThe reaction was quenched with methanol (0.5 mL) and water (5 mL)
  2. extractionextracted with ethyl acetate (3×15 mL)
  3. washThe combined organics were washed with brine (15 mL)
  4. dry with materialdried over sodium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-b13a9eb59af544ea83189249f96f86b4
Source dataset
uspto-grants-2015_07
Patent number
US09073871B2

Reaction notes

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