The Synthesis And Separation Of 5-(10-undecenethylamido)-acenaphthene

The enantiomers of all chiral molecules have to be isolated and to be tested for its difference in bioactivity, toxicity and the mechanism of metabolizability. The separation of enantiomers by chromatography on chiral stationary phases (CSPs) has been recognized as being a powerful alternative to the more conventional approaches such as enantioselective synthesis and enzymatically catalyzed transformations.In this paper Pirkle's chiral stationary phases is chiefly investigated. According to chem-structures and chiral resolution mechanism of Pirkle's CSP, a novel chiral substance 5-(10-undecenethylamido)-acenaphthene derived from acenaphthene has been prepared. The synthetic approach to the 5-(10-undecene thylamido)acenaphthene is via acetylation reaction to the acenaphthyl ring, deoxi amine reaction to the ketone, acetylation reaction to the amidocyanogen. All reaction conditions were studied and the best one are chosen.There is, to date, no paper on HPLC resolution of 5-(10-undecenethylamido) acenap hthene In order to get the single enantiomers of 5-(10-undecenethylamido) acenaphthene, the enantiomers are directly separated by chromatography on chiral stationary phases. Chiral resolution coefficients are investigated in different mobile phases, flow rate and temperature and we got the HPLC conditions of a =1.09, which uaually furnishes both enantiomers in high optical purity, but need much solvent. So we found a novel resolution reagent R-Thiazolidine-2-thione-4-carboxylic acid to separate 5-ethylaminoacenaphthene, which could provide better results.In experiments the scheme of preparation and resolution 5-(10-undecene thylamido)-acenaphthene is ensured. Experimental observations indicated that the resolving agent R(-)-TTCA provides excellent chiral recognition to 5-ethylamino acenaphthene. We got S(-) -5-ethylaminoacenaphthene, yield 72%, [ a ] =41. 0 ; R (-) -5-ethylaminoacenaphthene, yield 80%, [ a ] =-24. 2 ; R (-) -5- (10-undecenethylamido)- acenaphthene, [ a ] D20=-23.1 , S(+) - 5 - (10-undecenethy lamido)-acenaphthene, [a] D20 = +27. 6 . So we synthesized and separated 5-ethylaminoacenaphthene with R-TTCA, then produced optical pure 5-(10-undecenethylamido)-acenaphthene, which reduced the cost of resolution in HPLC.