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:
Sep. 08, 1987
Filed:
Dec. 18, 1985
Robert K Driscoll, Frankfurt am Main, DE;
Ernst I Leupold, Neu-Anspach, DE;
Wolfgang Ebertz, Bonn, DE;
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Abstract
The invention relates to a process for the preparation of glyoxylic hemiacetal esters, in which first glycolic esters are oxydehydrogenated to give glyoxylic esters, and then the latter are reacted with an alcohol. The gaseous reaction mixture formed in the oxydehydrogenation is introduced, together with an excess of an alcohol which is suitable as an entraining agent, into a distillation column and then the water of reaction is distilled overhead together with other low-boilers and part of the excess alcohol, the glyoxylic hemiacetal ester and the remainder of the excess alcohol resulting as the bottom product. In a variant of the process, use is made of an additional inert entraining agent whose azeotrope with water boils below 90.degree. C. and below the alcohol which is used, and then the water of reaction is distilled overhead with the assistance of this entraining agent.