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. 23, 1999
Filed:
Oct. 29, 1997
Applicant:
Inventors:
Karl Heinz Giselbrecht, Pasching, AT;
Klaus Reiter, Linz, AT;
Eduard Perndorfer, Traun, AT;
Rudolf Hermanseder, Pennewang, AT;
Assignee:
DSM Chemie Linz GmbH, , AT;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
568430 ; 568425 ;
Abstract
Process for the purification of o-phthalaldehyde in which an alcoholic solution containing the crude, unpurified o-phthalaldehyde is adjusted to a pH between 0 and 3 at a temperature between 0.degree. and 60.degree. C., then an alkaline solution is added, and the corresponding dialkoxyphthalan is extracted from the organic phase and purified by distillation and, when required, converted into the purified o-phthalaldehyde by hydrolysis.