Synthesis of a chiral macrocyclic dibenzodicyclohexanotetraamide-containing stationary phase for liquid chromatography

Allyloxy-substituted macrocyclic dibenzodicyclohexanotetraamide 2 was prepa red by the following sequence. MonoBoc-protected chiral 1,2-cyclohexanediam ine (3) was treated with isophthaloyl chloride followed by removal of the B oc group to form bisisophthalamide 5. Compound 5 was then treated with ally loxyphthaloyl chloride to form the macrocyclic tetraamide 2 in a 56% yield. Chiral selector 2 was converted to its ethoxydimethylsilane derivative and heated in a suspension of silica gel and toluene to form the chiral macroc ycle-containing silica gel phase 1. This phase separated the enantiomers of (+/-)-alpha-methylbenzylamine and (+/-)-DL-alpha-aminobutyric acid methyl ester in a liquid chromatograph.