Process for preparing cross-bridged tetraaza macrocycles
US6555681B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 14, 2001 |
| Grant date | Apr 29, 2003 |
| Priority date | — |
| Expiry date | May 14, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D487/08
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The present invention relates to a process for preparing a cross-bridged tetraaza macrocyclic ligands having formula (I), wherein each R is independently C1-C22 linear alkyl, C1-C22 branched alkyl, C7-C22 alkylenearyl, C8-C22 alkyl substituted alkylenearyl, and mixtures thereof; each index n is independently from 0 to 3, by contacting the a di-quaternary cis tetracycle precursor with as little as one equivalent of a borohydride reducing agent. The present process eliminates the need to use up to a twenty fold excess of reducing agent thereby further eliminating the need for work-up conditions which liberate significant amounts of hydrogen gas and which requires the disposal of large amounts of boron waste products.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.