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. 28, 2000
Filed:
May. 24, 1999
Giorgio Ripa, Milan, IT;
Alessandro Scala, Milan, IT;
Marcella Murru, Milan, IT;
Carlo Felice Viscardi, Milan, IT;
Marina Ausonio, Milan, IT;
Chiara Scotti, Milan, IT;
Patrizia Cossutta, Milan, IT;
Dibra S.p.A., , IT;
Abstract
A process for the preparation of complexes of macrocyclic chelants with paramagnetic metal trivalent ions of formula (XII) ##STR1## wherein R.sub.1, R.sub.2 and Me.sup.3+ are as described in the following, comprising: a) reaction of 1,4,7,10-tetraazacyclododecane with triethyl orthoformate to give 5H,9bH-2a,4a,7,9a-octahydrotetraazacycloocta[cd]pentalene; b) carboxymethylation reaction in water; c) hydrolysis reaction in basic conditions; d) alkylation according to known methods with an epoxide in water; e) complexation according to known methods carried out in water by addition of a paramagnetic metal salt; f) purification by diafiltration, final desalting of the aqueous solution on ion exchange resins and g) crystallization or recovery.