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:
Jul. 20, 1999
Filed:
Jan. 09, 1998
James Philip Taylor, Macclesfield, GB;
William Walker, Manchester, GB;
John Whitworth, Manchester, GB;
Michael Heneghan, Salford, GB;
Ciba Specialty Chemicals Corporation, Tarrytown, NY (US);
Abstract
A method for the production of a keto acid having the general formula ##STR1## wherein R1 and R2 independently represent a straight or branched chain alkyl of 1-18 carbon atoms, a cycloalkyl of 4-8 carbon atoms or a phenyl, each of which may be substituted by at least one substituent selected from the group consisting of halogen atoms and alkyls having 1-4 carbon atoms, an aralkyl of 7-10 carbon atoms, alkoxyalkyl having 2-20 carbon atoms, tetrahydrofuryl alkyl, alkylcarboxy alkyl, alkylcarboxy benzyl, or R1 and R2 together with the adjacent nitrogen atom may form a heterocyclic ring, or one of R.sub.1 and R.sub.2 is hydrogen, but R1 and R2 may not simultaneously be methyl or ethyl or benzyl which comprises reacting a m-amino phenol having the general formula ##STR2## wherein R1 and R2 are the same as above, with phthalic anhydride, in an organic solvent in an amount of less than 0.5 parts by weight per part of m-amino phenol.