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:
Jul. 13, 2010
Filed:
Nov. 18, 2009
Lars Terje Holmaas, Spangereid, NO;
Kristin Rypestol, Mandal, NO;
Lars Terje Holmaas, Spangereid, NO;
Kristin Rypestol, Mandal, NO;
GE HealthCare AS, Oslo, NO;
Abstract
This invention relates to an improved method for crystallizing 5-acetamido-N,N'-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophthalamide ('Compound A'), an intermediate in the industrial preparation of non-ionic X-ray contrast agents. In particular, the present invention provides an industrial process for crystallization of Compound A by evaporating methanol and water from the mother liquor after an initial crystallization of Compound A following the acetylation reaction. Specifically, the mother liquor is maintained at more than about 75% (v/v) of water and less than about 25% (v/v) of alcoholic solvent.