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:
Dec. 03, 1996
Filed:
Sep. 12, 1994
Marco Villa, Milan, IT;
Antonio Nardi, Cusano Milanino, IT;
Zambon Group S.p.A., Vicenza, IT;
Abstract
A process for the preparation of Iopamidol and 5-amino-2,2-dialkyl-1,3-dioxanes of formula ##STR1## wherein R and R.sub.1 are the same or different and represent a straight or branched C.sub.1 and C.sub.2 alkyl group or together with the carbon atom to which they are bonded, form a C.sub.5 -C.sub.6 cycloaliphatic ring; comprising the transformation of a 2,2-dialkyl-1,3-dioxane-5-carboxylic acid ester of formula ##STR2## wherein R.sub.2 represents a straight or branched C.sub.1 -C.sub.2 alkyl group, a phenyl optionally substituted by nitro groups or a benzyl; by treatment with ammonia into the corresponding amides and the subsequent rearrangement of the latter into the compounds of formula I, by treatment with a hypohalogenite. The resultant ketals may be used as is, or be converted to 2-amino-1,3-propanediol, and reacted with 5-amino-2,4,6-triiodo-isophthalic acid dichloride or, alternatively,L-5-(2-acetoxy-propionylamino)-2,4,6-triido-isophthalic acid dichloride, to produce Iopamidol.