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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 654514Generated: 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/654514

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 numberUS05132310
Source datasetuspto-grants-1992_07
ORD IDord-12b61da4b3964af28daa966ef1cf5935
Source noteuspto-grants-1992_07