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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 65683Generated: October 25, 2026

Ethyl propiolate → 5,6-Dihydro-5-oxopyrazolo[1,5-c]quinazoline-2-carboxylic acid ethyl ester

https://huagongshe.com/reaction/65683

Reaction equation

Participants

RoleNameHCIDCharge
ReactantEthyl propiolateHCID 12182—
Reactant(3Z)-3-diazo-1H-indol-2-oneHCID 136455454—
SolventBenzeneHCID 241—
Product5,6-Dihydro-5-oxopyrazolo[1,5-c]quinazoline-2-carboxylic acid ethyl esterHCID 136023344—

Reaction Steps

A solution of 48 g (0.30 mole) of 3-diazooxindole and 38.7 g (0.39 mol) of ethyl propiolate in 2 l. of benzene is refluxed overnight. The reaction mixture is cooled to room temperature and the crude product filtered, wt.=60 g. Crystallization from absolute ethanol gives 54 g, m.p. 242°-244° (Sl. d.).

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS04128644
Source datasetuspto-grants-1978_12
ORD IDord-3d803840950b476982579113b263d705
Source noteuspto-grants-1978_12