Boron tribromide → 2-(4-Hydroxyphenyl)-5-methyl-2H-pyrazole-3-carboxylic acid ethyl ester

HRID 598779Notes

Reaction equation

HRID 598779 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[N:7]([C:12]2[CH:17]=[CH:16][C:15]([O:18]C)=[CH:14][CH:13]=2)[N:8]=[C:9]([CH3:11])[CH:10]=1)=[O:5])[CH3:2].B(Br)(Br)Br>C(Cl)Cl>[CH2:1]([O:3][C:4]([C:6]1[N:7]([C:12]2[CH:13]=[CH:14][C:15]([OH:18])=[CH:16][CH:17]=2)[N:8]=[C:9]([CH3:11])[CH:10]=1)=[O:5])[CH3:2]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 11021617Ethyl 1-(4-methoxyphenyl)-3-methyl-1H-pyrazole-5-carboxylate

Product 1

HCID 589487762-(4-Hydroxyphenyl)-5-methyl-2H-pyrazole-3-carboxylic acid ethyl esterYield 67.7%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
-40 °C

Procedure

To a solution of 2-(4-methoxyphenyl)-5-methyl-2H-pyrazole-3-carboxylic acid ethyl ester (200 mg, 0.768 mmol, Example 10, Step 1) in methylene chloride (10 mL) at −40° C. was added boron tribromide (2.3 mL). The reaction was allowed to stir for 1 hour at −40° C. and for an additional hour while warming to room temperature. The reaction was quenched with ethanol diluted with water and methylene chloride. The organic layer was dried (MgSO4) and concentrated to give 128 mg of the desired product. LC-MS (C13H14N2O3 calculated 246) m/z 247 (M+H).

Workup

  1. temperaturewhile warming to room temperature
  2. customThe reaction was quenched with ethanol
  3. additiondiluted with water and methylene chloride
  4. dry with materialThe organic layer was dried (MgSO4)
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-e0caf069db084b379646ae21254c8d78
Source dataset
uspto-grants-2011_03
Patent number
US07897634B2

Reaction notes

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