The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 12, 1991
Filed:
Aug. 31, 1989
Jerry R Patton, Ballwin, MO (US);
Narayanasamy Gurusamy, Ballwin, MO (US);
Mallinckrodt, Inc., St. Louis, MO (US);
Abstract
Disclosed is a practical and efficient process for preparing 6-substituted 4-chromanones from phenolic acrylate ester compounds derivable from para-substituted phenolic or thiophenolic compounds and beta-unsubstituted acrylic acid compounds which are esterifiable therewith. The process includes effecting rearrangement of a phenolic or thiophenolic acrylate ester in the presence of a rearrangement effective amount of hydrogen fluoride to the corresponding hydroxy--or mercapto (vinyl ketone) wherein the carbonyl carbon atom of the vinyl carboxy group is directly attached to the benzene ring ortho to the hydroxy or mercapto group. Thereafter, the vinyl ketone is cyclized to the corresponding 6-substituted 4-chromanone in the presence of a cyclization-effective amount of hydrogen fluoride. The 6-substituted 4-chromanones prepared by the process are useful as intermediates for preparing pharmaceutical agents.