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:
Dec. 31, 1985
Filed:
Sep. 21, 1984
Visweswara R Durvasula, Cheshire, CT (US);
The UpJohn Company, Midland, MI (US);
Abstract
A method is described for autoxidizing particular ortho-dialkyl substituted aromatic compounds using a particular type of solvent which gives rise to the formation of 3-alkanoyloxyphthalide compounds, some of which are novel. The phthalides in turn are ionically oxidized to their corresponding aromatic polycarboxylic acids. Combination of the two methods provides a means for converting ortho dialkyl substituted aromatic compounds directly to the corresponding polycarboxylic acids in higher yields and at generally lower overall temperatures and reaction conditions compared to prior art methods. Polycarboxylic acids so obtained are known to be useful in the preparation of alkyds, polyesters, and the like, and, particularly, in the formation of the corresponding acid anhydrides which are used in the preparation of organic high temperature polymers such as polyamides, polyamideimides, and polyimides.