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. 15, 1992
Filed:
Nov. 15, 1990
Applicant:
Inventor:
Robert G Schultz, St. Louis, MO (US);
Assignee:
Monsanto Company, St. Louis, MO (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
562583 ;
Abstract
There is disclosed herein an improved processes for the preparation of oxydisuccinate by reacting in an alkaline reaction medium the salts of maleic acid and malic acid in the presence of a calcium ion catalyst wherein unreacted maleic acid salts are recovered from the reaction medium as sodium hydrogen maleate by lowering the pH of the reaction product to a range of from about 4 to 6. The precipitated sodium hydrogen maleate salts are recycled to the synthesis reaction as salts of malic acid by hydration in the presence of a hydration catalyst to prepare additional amounts of product.