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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 1708019Generated: October 30, 2026

Ethyl formate → 4,5-Dihydro-3-(4-fluorophenyl)-5-oxo-2-(pyridin-4-yl)pyrazolo[1,5-a]pyrimidine

https://huagongshe.com/reaction/1708019

Reaction equation

Participants

RoleNameHCIDCharge
ReactantEthyl formateHCID 8025—
ReactantEthyl AcetateHCID 8857—
ReactantSodiumHCID 5360545—
ReactantHCID 178509114HCID 178509114—
SolventEthanolHCID 702—
SolventTolueneHCID 1140—
Product4,5-Dihydro-3-(4-fluorophenyl)-5-oxo-2-(pyridin-4-yl)pyrazolo[1,5-a]pyrimidineHCID 136378416—

Reaction Steps

A mixture of sodium (28 mg), ethyl acetate (0.12 ml) and ethyl formate (0.10 ml) in dry toluene (0.5 ml) was stirred at ambient temperature for 14 hours under nitrogen. To the mixture was added 5-amino-4-(4-fluorophenyl)-3-(pyridin-4-yl)pyrazole (150 mg) in dry ethanol (1.5 ml) and the mixture was refluxed for 7 hours. The reaction mixture was cooled and the separated solid was collected and dried. The solid was dissolved in water (15 ml) and the solution was washed with ether. The aqueous solution was neutralized with diluted hydrochloric acid. The separated solid was collected, washed with water and dried to give 4,5-dihydro-3-(4-fluorophenyl)-5-oxo-2-(pyridin-4-yl)pyrazolo[1,5-a]pyrimidine (62 mg).

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS05356897
Source datasetuspto-grants-1994_10
ORD IDord-7ebb5db456084a209b59ee1b7afb289d
Source noteuspto-grants-1994_10