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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 1499106Generated: November 2, 2026

1-Bromo-4-chloro-2-fluorobenzene → HCID 25212417, compound

https://huagongshe.com/reaction/1499106

Reaction equation

Participants

RoleNameHCIDCharge
Reactant1-Bromo-4-chloro-2-fluorobenzeneHCID 137275—
ReactantPotassium tert-butoxideHCID 23665647—
ReactantHCID 178428694HCID 178428694—
SolventDimethyl SulfoxideHCID 679—
ProductHCID 25212417HCID 25212417—
Product1-(2-bromo-5-chlorophenyl)-5-methyl-1H-pyrazoleHCID 57609541—

Reaction Conditions

Temperature50 °C

Reaction Steps

Potassium t-butoxide (3.9 g, 0.33 mmol) was dissolved in DMSO (25 mL). To this solution was added 3-methylpyrazole (2.7 g, 0.33 mmol) and the reaction was heated at 50° C. for 30 min. 1-Bromo-4-chloro-2-fluorobenzene (4.6 g, 0.22 mmol) was then added and the reaction was stirred at 50° C. for 16 h. The reaction was cooled to RT and extracted with water and EtOAc, washed with brine, and dried over Na2SO4, filtered and concentrated in vacuo. Purification by normal phase silica gel column chromatography (EtOAc/heptane) provided 1-(2-bromo-5-chlorophenyl)-3-methyl-1H-pyrazole and 1-(2-bromo-5-chlorophenyl)-5-methyl-1H-pyrazole as a 4:1 mixture that was used in the next step directly.

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS09199994B2
Source datasetuspto-grants-2015_12
ORD IDord-00ee8b2838d8438391b49ff0abd64f8c
Source noteuspto-grants-2015_12