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. 04, 1997
Filed:
Feb. 01, 1994
Applicant:
Inventors:
Shinri Tanaka, Tokyo, JP;
Yasuhiko Kawashima, Tokyo, JP;
Assignee:
Konica Corporation, Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ; C07D / ; C07D / ;
U.S. Cl.
CPC ...
540454 ; 540456 ; 540467 ; 540468 ; 540469 ; 549 11 ; 549348 ; 549351 ; 549352 ; 549353 ;
Abstract
A process of preparing a purified crown compound is disclosed which comprises the steps of (a) dissolving a crown compound and a salt in an organic solvent to form a solution of a complex salt of a crown compound; (b) filtering the solution to obtain a filtrate; (c) adding water to the filtrate to produce a precipitate; and (d) filtering out the produced precipitate.