| 摘要 |
<p>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.</p> |
