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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 598779Generated: October 29, 2026

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

https://huagongshe.com/reaction/598779

Reaction equation

Participants

RoleNameHCIDCharge
ReactantBoron tribromideHCID 25134—
ReactantEthyl 1-(4-methoxyphenyl)-3-methyl-1H-pyrazole-5-carboxylateHCID 11021617—
SolventDichloromethaneHCID 6344—
Product2-(4-Hydroxyphenyl)-5-methyl-2H-pyrazole-3-carboxylic acid ethyl esterHCID 5894877667.7%

Reaction Conditions

Temperature-40 °C

Reaction Steps

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).

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS07897634B2
Source datasetuspto-grants-2011_03
ORD IDord-e0caf069db084b379646ae21254c8d78
Source noteuspto-grants-2011_03