Regioselective preparation and NMR spectroscopy study of 2-chloro-4-ethoxy-quinoline for the synthesis of 2-((3-aminopropyl)amino)quinolin-4(1H )-one
| Autor: | Jessie Sobieski da Costa, Rodrigo dos Santos Fuscaldo, Francisco Prado Eugenio dos Santos, Pedro Henrique Vasconcelos Vontobel |
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| Rok vydání: | 2019 |
| Předmět: |
Sodium ethoxide
010405 organic chemistry Quinoline Ether General Chemistry Nuclear magnetic resonance spectroscopy 010402 general chemistry 01 natural sciences Medicinal chemistry 0104 chemical sciences chemistry.chemical_compound chemistry Heteronuclear molecule Alkoxy group Dimethylformamide General Materials Science Selectivity |
| Zdroj: | Magnetic Resonance in Chemistry. 58:295-304 |
| ISSN: | 0749-1581 |
| DOI: | 10.1002/mrc.4980 |
| Popis: | Herein, we describe the C4-ethoxylation of 2,4-dichloroquinoline to prepare 2-chloro-4-ethoxy-quinoline (3), which is a prominent intermediate used for the synthesis of 2-substituted quinolones. To achieve this goal, we studied different conditions for the reaction between 2,4-dichloroquinoline and sodium ethoxide. We discovered that the use of 18-crown-6 ether as an additive and dimethylformamide as the reaction solvent allowed us to obtain the desired product 3 in very good yield and selectivity. In addition, a definitive distinction between the C2 and C4 ethoxylation products was achieved using 1 H─15 N heteronuclear multiple bond correlation. Compound 3 is an intermediate used for the synthesis of 2-((3-aminopropyl)amino)quinolin-4(1H)-one, which displays peculiar behavior during 1 H nuclear magnetic resonance analysis, such as the broadening of the H8 singlet and unexpected deuteration at the C8-position. Effort has been dedicated to understand these findings. |
| Databáze: | OpenAIRE |
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