The methods of synthesis, modification, and biological activity of 4-quinolones (review)

Abstract

Data on methods for the construction of the 4-quinolone skeleton and modification of the substituents around it are reviewed. The "structure-activity" relationships of 4-quinolones are examined with respect to antibacterial and antitumor activity.Keywords: 4-quinolones, biological activity. 4-Quinolones have been a subject of research for many scientific teams, and this is reflected in the numerous reviews and monographs devoted to various aspects of the subject. One of the early reviews [1] concerns aspects of the synthesis of individual representatives of the group of 4-quinolones and comparative characterization of their antimicrobial activity. Basic approaches to construction of the fluoroquinolone skeleton and also variation of the substituents at various positions of the ring were examined in the review [2]. The relationship between the structure and antibacterial activity is discussed in [3], and methods for the synthesis of polycyclic derivatives of 4-quinolones based on the annelation of rings to the various faces of the quinoline skeleton are discussed in the review [4]. The reviews [5, 6] were devoted to identification of the structural modifications of 4-quinolones responsible for their conversion from antibacterial agents to antitumor agents. The molecular and biological aspects of the antibacterial action of 4-quinolone-3-carboxylic acids are examined in [7], and issues concerned with the clinical application of 4-quinolones are discussed in the reviews [8][9][10][11][12] and in the monograph [13]. The synthesis and the "structure-activity" relationships of the bioisosteres of 4-quinolones -2-pyridones -are examined in the review [14].The aim of the present review was to classify existing methods for the synthesis not only of fluoroquinolones but also of any 4-quinolones, to demonstrate the effects of modification of the molecule at all positions, to summarize data on the various types of activity, and to examine the "structure-activity" relationship with respect to antibacterial and antitumor activity.

Efficient synthesis of novel thieno[3,2-b]-, [2,3-c]- and [3,2-c]pyridones by Sonogashira coupling of bromothiophenes with terminal alkynes and subsequent intramolecular C–N bond-forming reaction

“…General procedure for the synthesis of 3-(aryl/alkylethynyl) thiophene-2-carboxamides (5). An ethanol solution (10 ml) of the corresponding compound 4 (0.1 g) was saturated with aqueous ammonia and heated for 10e12 h in a pressure tube at 70 C. After completion of the reaction, solvent was removed under reduced pressure and the residue was purified with silica gel column chromatography.…”

Synthesis of 9-ethyl[1,2,5]selenadiazolo[3,4-h]quinolones by the application of modified Gould-Jacobs reaction to N-ethyl-2,1,3-benzoselenadiazol-4-amine

“…The resulting orange oil was subjected to FLC (SiO 2 , EtOAc/hexanes 1:4, R f 0.25) to afford compound 14 (7.2 g, 97%) as yellow oil. 1 …”

“…1,2 In the last decades, anti-cancer activity of 4-quinolone derivatives has been revealed and studied intensively. 3,4 The presence of selenium in the structure of 4-quinolones can bring new characteristics, and plenty of selenaheterocyclic compounds showed positive biological impact.…”

Synthesis of (1-ethyl-2-phenyl-1,4-dihydroquinolin-4-yl)-(2,4,6-trimethylphenyl)-amine by Electrochemical Methods in Aprotic Media

“…2-phenylquinolin-1-ethyl-4-one was prepared according to reported method. 16 Stock solution of imine (Q=NAr) were prepared at a concentration of 1×10 -3 mol dm -3 in DMF. The supporting electrolyte of tetrabutylammonium bromide (TBAB) was purchased from SISCO Research laboratories Pvt.…”