Synthesis of 3,4-dihydropyrimidinone compounds and their chiral recognition on polysaccharide chiral stationary phases

Večenaj, Ivana (2015) Synthesis of 3,4-dihydropyrimidinone compounds and their chiral recognition on polysaccharide chiral stationary phases. Doctoral thesis, Faculty of Science > Department of Chemistry.

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Abstract

Two reaction protocols based on use of hexaaquaaluminium(III) tetrafluoroborate and copper(II) benzensulphonate tetrahydrate are optimized for synthesis of 3,4-dihydropyrimidinone (3,4-DHPM). Regardless the characteristics of reactants, high yields were achieved. While reaction catalyzed by [Al(H2O)6](BF4)3 includes formation of ureido-crotonate, reaction catalyzed by [Cu(C6H5SO3)2]×4H2O includes formation of acylimino intermediate. According to results obtained by enantioselective chromatographic analysis of 3,4-DHPM compounds on different polysaccharide chiral stationary phases (CSPs), the best resolutions are achieved using 3,5-dimethylphenyl carbamoyl amylose CSPs. Also, different mechanism of chiral recognition is established while using ethanol or propan-2-ol as modifier. With ethanol as modifier, chiral recognition is contributed by para-substitution of aryl ring of 3,4-DHPM, with both electron-withdrawing and electron-donating substituents, by hydrogen bond between NH group of DHPM ring and C=O group of CSP and by hydrogen bond between C=O group of DHPM ring and NH group of CSP. π-π interactions of analyte and CSP play significant role in retention mechanism of second elution enantiomers. With propan-2-ol, the best chiral recognitions are achieved for para-methoxy substituted 3,4-DHPM. In case of this modifier, hydrogen bond which involves NH group of DHPM ring is weaker than one that includes C=O group. With propan-2-ol π-π interactions of analyte and CSP do not contribute to chiral recognition.

Item Type: Thesis (Doctoral thesis)
Keywords: [Al(H2O)6](BF4)3, [Cu(C6H5SO3)2]×4H2O, CSP, 3,4-DHPM, enantioselective chromatography, hydrogen bond, π-π interactions
Supervisor: Vinković, Vladimir and Litvić, Mladen
Date: 2015
Number of Pages: 252
Subjects: NATURAL SCIENCES > Chemistry
Divisions: Faculty of Science > Department of Chemistry
Depositing User: Branka Maravic
Date Deposited: 14 Jan 2016 10:41
Last Modified: 14 Jan 2016 10:41
URI: http://digre.pmf.unizg.hr/id/eprint/4438

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