http://hdl.handle.net/20.500.12128/13731
Tytuł: | Synthesis, electrochemical and spectroscopic characterization of selected quinolinecarbaldehydes and their Schiff base derivatives |
Autor: | Wantulok, Jakub Szala, Marcin Quinto, Andrea Nycz, Jacek E. Giannarelli, Stefania Sokolová, Romana Książek, Maria Kusz, Joachim |
Słowa kluczowe: | vilsmeier-haack; reimer-tiemann; duff; aldehyde; aldazine; heterocyclic; cyclic voltammetry |
Data wydania: | 2020 |
Źródło: | Molecules, 2020, iss. 9, art. no. 2053 |
Abstrakt: | A new approach to the synthesis of selected quinolinecarbaldehydes with carbonyl groups located at C5 and/or in C7 positions is presented in this paper in conjunction with spectroscopic characterization of the products. The classical Reimer-Tiemann, Vilsmeier-Haack and Duff aldehyde synthesis methods were compared due to their importance. Computational studies were carried out to explain the preferred selectivity of the presented formylation transformations. A carbene insertion reaction based on Reimer-Tiemann methodology is presented for making 7-bromo-8-hydroxyquinoline-5-carbaldehyde. Additionally, Duff and Vilsmeier-Haack reactions were used in the double formylation of quinoline derivatives and their analogues benzo[h]quinolin-10-ol, 8-hydroxy-2-methylquinoline-5,7-dicarbaldehyde, 8-(dimethylamino) quinoline-5,7-dicarbaldehyde and 10-hydroxybenzo[h]quinoline-7,9-dicarbaldehyde. Four Schiff base derivatives of 2,6-diisopropylbenzenamine were prepared from selected quinoline-5-carbaldehydes and quinoline-7-carbaldehyde by an efficient synthesis protocol. Their properties have been characterized by a combination of several techniques: MS, HRMS, GC-MS, FTIR, electronic absorption spectroscopy and multinuclear NMR. The electrochemical properties of 8-hydroxy-quinoline-5-carbaldehyde, 6-(dimethylamino)quinoline-5-carbaldehyde and its methylated derivative were investigated, and a strong correlation between the chemical structure and obtained reduction and oxidation potentials was found. The presence of a methyl group facilitates oxidation. In contrast, the reduction potential of methylated compounds was more negative comparing to non-methylated structure. Calculations of frontier molecular orbitals supported the finding. The structures of 8-hydroxy-2-methylquinoline-5,7-dicarbaldehyde and four Schiff bases were determined by single-crystal X-ray diffraction measurements. |
URI: | http://hdl.handle.net/20.500.12128/13731 |
DOI: | 10.3390/molecules25092053 |
ISSN: | 1420-3049 |
Pojawia się w kolekcji: | Artykuły (WNŚiT) |
Plik | Opis | Rozmiar | Format | |
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Wantulok_Synthesis_electrochemical.pdf | 1,55 MB | Adobe PDF | Przejrzyj / Otwórz |
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