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:
Mar. 23, 1993
Filed:
May. 30, 1991
Applicant:
Inventors:
Karl Schermanz, Graz, AT;
Klaus Fitzinger, Linz, AT;
Assignee:
Chemie Linz Gesellschaft m.b.H., Linz, AT;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
5483181 ;
Abstract
Process for the preparation of allantoin in a two-stage reaction by reaction of methyl glyoxylate methyl hemiacetal with urea in the presence of an inorganic acid at a pH-value of 1.0-2.0 and carrying out the ring-closure reaction at a pH-value of 7.0 to 9.0 in a second reaction stage.