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. 31, 1996
Filed:
Jun. 07, 1995
Rolf W Sandnes, Oslo, NO;
Kjell Undheim, Oslo, NO;
Michel Gacek, Oslo, NO;
Janis Vasilevskis, Wayne, PA (US);
Nycomed Imaging AS, Oslo, NO;
Abstract
The present invention provides a synthetic route for tetraazacycloalkane preparation which facilitates heteropoly-N-alkylation of the macrocyclic product, and is thereby beneficial for the production of chelating agents and chelates useful in diagnostic imaging. The process involves (i) reacting a tetraazaalkane with a bridging agent to couple four amine nitrogens of said tetraazaalkane to a bridging moiety to yield a fused tricyclic intermediate, (ii) reacting said intermediate to introduce an alkylene bridge between the secondary amine nitrogens in the outer rings of the fused tricyclic intermediate, optionally by decoupling an alkanediylidene bridging moiety from the tertiary amine nitrogens at the ring fusion sites of the fused tricyclic intermediate, and (iii) where necessary, decoupling said bridging moiety to yield a macrocyclic tetraazacycloalkane.