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:
Sep. 01, 1998
Filed:
Nov. 12, 1997
David Xu, Whippany, NJ (US);
Prasad Kapa, Parsippany, NJ (US);
Oljan Repic, Randolph, NJ (US);
Thomas J Blacklock, Clark, NJ (US);
Johnson Matthey PLC, London, GB;
Abstract
An improved process for preparing 1,1'-�1,4-phenylenebis-(methylene)!-bis-1,4,8,11-tetraazacyclotetradecane comprising the selective functionalization of an acyclic tetraamine, and subsequent dimerization and hydrolyzation/tosylation to obtain a 1,4-phenylenebis-methylene bridged hexatosyl acyclic precursor in a first step, the cyclization of said precursor to obtain a hexatosyl cyclam dimer in a second step, and the detosylation of said cyclam dimer in a third step followed by basification to obtain the desired 1,1'-�1,4-phenylenebis-(methylene)!-bis-1,4,8,11-tetraazacyclotetradecane.