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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 2263359Generated: October 27, 2026

Pyridine → 5-Chloro-3-phenyl-1,2,4-oxadiazole

https://huagongshe.com/reaction/2263359

Reaction equation

Participants

RoleNameHCIDCharge
ReactantPyridineHCID 1049—
ReactantPhosphorus oxychlorideHCID 24813—
Reactant3-Phenyl-1,2,4-oxadiazol-5(4H)-oneHCID 135418577—
Product5-Chloro-3-phenyl-1,2,4-oxadiazoleHCID 1272844352.7%

Reaction Conditions

Temperature100 °C

Reaction Steps

To a mixed solution of 3-phenyl-1,2,4-oxadiazol-5(4H)-one (2.00 g, 12.3 mmol) in phosphorus oxychloride (36 g) was added pyridine (1.93 ml, 23.9 mmol), and the mixture was stirred at 100° C. for 6 hours. The solvent was distilled off under reduced pressure. The residue was poured to ice water and extracted with ethyl acetate. The extract was washed with water and dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=2:1) to give 1.17 g (52.4%) of the desired product as a solid.

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS07851473B2
Source datasetuspto-grants-2010_12
ORD IDord-0d55a181e9ee40a9a84e9dddedf58690
Source noteuspto-grants-2010_12