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. 06, 1994
Filed:
Mar. 29, 1993
Masahiro Kondo, Yamaguchi, JP;
Michio Tanaka, Yamaguchi, JP;
Naoya Sakamoto, Yamaguchi, JP;
Hajime Ooyoshi, Yamaguchi, JP;
Mitsui Petrochemical Industries, Ltd., Tokyo, JP;
Abstract
In a method of producing a keto acid having the general formula ##STR1## wherein R.sup.1 and R.sup.2 independently represent an alkyl of 1-6 carbons or a cycloalkyl of 4-8 carbons, by reacting an m-aminophenol having the general formula ##STR2## wherein R.sup.1 and R.sup.2 are the same as above, with phthalic anhydride, in an organic solvent, the improvement comprising effecting the reaction in an amount of the organic solvent which is insufficient to dissolve the keto acid produced in the reaction, so that at least a portion of the resultant keto acid crystallizes out of the solvent and allowing the reaction to proceed in a heterogeneous system.