Department of Chemistry, Faculty of Technology, Tomas Bata University, Vavrečkova 275, 760 01, Zlín, Czech Republic.
Department of Chemistry, Faculty of Science, University of Hradec Králové, Rokitanského 62, 500 03, Hradec Králové 3, Czech Republic.
ChemistryOpen. 2021 Jun;10(6):645-652. doi: 10.1002/open.202100024.
3-Chloroquinoline-2,4-diones react with cyanide ions in dimethyl formamide to give 3-cyanoquinoline-2,4-diones in small yields due to the strong hindrance of the substituent at the C-3 atom. Good yields can be achieved if the substituent at this position is the methyl group. In the methanol solution, the reaction proceeds by an addition mechanism to form 2-oxo-1a,2,3,7b-tetrahydrooxireno[2,3-c]quinoline-7b-carbonitriles, from which 4-hydroxy-3-methoxy-2-oxo-1,2,3,4-tetrahydroquinoline-4-carbonitriles are subsequently formed by opening of the epoxide ring with methanol. Some minor products of these reactions have also been isolated. The H, C and N NMR spectra of the prepared compounds were measured, and all resonances were assigned using appropriate two-dimensional spectra.
3-氯喹啉-2,4-二酮与氰化物离子在二甲酰胺中反应，由于 C-3 原子上取代基的强烈位阻，只能得到少量的 3-氰基喹啉-2,4-二酮。如果该位置的取代基为甲基，则可以得到较好的产率。在甲醇溶液中，反应通过加成机理进行，形成 2-氧代-1a,2,3,7b-四氢氧杂环庚[2,3-c]喹啉-7b-甲腈，随后甲腈与甲醇开环形成 4-羟基-3-甲氧基-2-氧代-1,2,3,4-四氢喹啉-4-甲腈。这些反应也分离出了一些少量产物。所制备化合物的 1H、13C 和 15N NMR 谱均进行了测量，并使用适当的二维谱对所有共振峰进行了归属。
