Process for the preparation of iopamidol and 5-amino-2,2-dialkyl-1,3-dioxanes
US5580993A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 12, 1994 |
| Grant date | Dec 3, 1996 |
| Priority date | — |
| Expiry date | Sep 12, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D319/06
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.