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:
Nov. 14, 1989
Filed:
Aug. 03, 1988
Applicant:
Inventors:
Assignee:
Daiichi Seiyaku Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
544105 ;
Abstract
The invention relates to a process for producing a (.+-.)-3-alkyl-3,4-dihydro-2H-[1,4]benzoxazine derivate of formula (II) by stepwise racemization procedure. ##STR1## The invention further provides a process for optical resolution through the formation of a salt between a (.+-.)-benzoxazine compound and an optically active form of camphor-10-sulfonic acid. Without requiring the conventional expensive resolution reagents, this process not only assures production of an optically active isomer of compound (II) in high purity but also permits reuse of the optical resolution reagent.