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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 256866Generated: October 31, 2026

Acetic Anhydride → rac-6-Acetyloxy-3,4-dihydro-2,5,7,8-tetramethyl-2-(phenyl-ethynyl)-2H-1-benzopyran

https://huagongshe.com/reaction/256866

Reaction equation

Participants

RoleNameHCIDCharge
ReactantAcetic AnhydrideHCID 7918—
Reactant3,4-dihydro-2,5,7,8-tetramethyl-2-(2-phenylethynyl)-2H-1-benzopyran-6-olHCID 15171809—
SolventPyridineHCID 1049—
Productrac-6-Acetyloxy-3,4-dihydro-2,5,7,8-tetramethyl-2-(phenyl-ethynyl)-2H-1-benzopyranHCID 15171916—

Reaction Steps

A mixture of 0.3 g of rac-3,4-dihydro-2,5,7,8-tetramethyl-2-(phenylethynyl)-2H-1-benzopyran-6-ol, 7 ml of pyridine and 0.5 ml of acetic anhydride was allowed to sit at room temperature over night. The reagents were evaporated under reduced pressure, at the end azeotropically with toluene. The residue was crystallized from hexane to give 0.21 g of colorless crystals with m.p. 123°-125°.

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS05260294
Source datasetuspto-grants-1993_11
ORD IDord-24a8a6f034124ce9b2dc7efbf918a59f
Source noteuspto-grants-1993_11