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. 29, 1992
Filed:
May. 25, 1990
Applicant:
Inventors:
Mark T DuPriest, Fort Worth, TX (US);
Raymond E Conrow, Fort Worth, TX (US);
Daniel Kuzmich, Fort Worth, TX (US);
Assignee:
Alcon Laboratories, Inc., Fort Worth, TX (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C / ; C07C / ;
U.S. Cl.
CPC ...
560 10 ; 560 34 ; 560 45 ; 560 47 ; 560 48 ;
Abstract
Disclosed is a process for the synthesis of enantiomerically pure R and S isomers of 2,7-difluoro-4-methoxyspiro[9H-fluorene-9,4-imidazolidene]-2',5'-dione from 2,7-difluoro-4-methoxyfluorenone. Intermediate amino acid esters and urea esters and their preparation are also described.