Novel One-Pot Synthesis of Methyl 4-Hydroxy-2-thioxo-1,2-dihydroquinoline-3-carboxylate: Synthetic and Crystallographic Studies

• Published in: MolBank Vol. 2019; no. 4; p. M1085
• Main Authors: Kovalenko, Sergiy M., Drushlyak, Oleksandr G., Konovalova, Irina S., Mariutsa, Illia O., Kravchenko, Dmitry V., Ivachtchenko, Alexandre V., Mitkin, Oleg D.
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01-12-2019
• Subjects: Acids; Benzoates; Carbon; Carbonyls; Chemical analysis; Condensates; condensation; Crystal structure; Crystallography; Hydrogen bonds; Infrared spectroscopy; isothiocyanate; malonic ester; NMR; Nuclear magnetic resonance; quinoline; Single crystals; Sodium; Solvents; Synthesis; Switzerland
• ISSN: 1422-8599; 1422-8599
• DOI: 10.3390/M1085

A new suitable method of synthesis of methyl 4-hydroxy-2-thioxo-1,2-dihydroquinoline-3-carboxylate by condensation of methyl 2-isothiocyanatobenzoate and methyl malonate is described. The structure of the compound both and by-product methyl 2-(methoxycarbonothioylamino)benzoate was confirmed by means of elemental analysis, 1H NMR, 13C NMR, LC/MS and single crystal X-ray diffraction. UV/Vis and IR spectra of compounds are described. The presence of a strong intramolecular hydrogen bond between the hydroxy group and the carbonyl oxygen atom of the ester group in methyl 4-hydroxy-2-thioxo-1,2-dihydroquinoline-3-carboxylate is shown. The crystal structure of product was stabilized through intermolecular hydrogen bonds.