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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 1181866Generated: October 25, 2026

1,2-Dibromoethane → 7-Bromo-2-ethyl-4-methoxypyrazolo[1,5-a]pyridine

https://huagongshe.com/reaction/1181866

Reaction equation

Participants

RoleNameHCIDCharge
Reactant1,2-DibromoethaneHCID 7839—
ReactantAmmonium ChlorideHCID 25517—
Reactant2-Ethyl-4-methoxypyrazolo[1,5-a]pyridineHCID 21984578—
ReactantButyllithiumHCID 178418339—
SolventTetrahydrofuranHCID 8028—
Product7-Bromo-2-ethyl-4-methoxypyrazolo[1,5-a]pyridineHCID 21984567—

Reaction Conditions

Temperature-78 °C

Reaction Steps

n-Butyllithium (1.31 mL) was slowly added dropwise to a solution of 2-ethyl-4-methoxypyrazolo[1,5-a]pyridine (303 mg) in tetrahydrofuran (15 mL) at −78° C. After stirring the mixture at −78° C. for 1 hour, 1,2-dibromoethane (0.18 mL) was added and stirring was continued for 1 hour. Saturated aqueous ammonium chloride was added, extraction was performed with ethyl acetate, the extract was washed with brine and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography (20 g), and the title compound (282 mg) was obtained from the n-hexane:ethyl acetate (5:1) fraction as a colorless oil.

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS07285666B2
Source datasetuspto-grants-2007_10
ORD IDord-00f69cf14788421e96a6c13393a930a5
Source noteuspto-grants-2007_10