Synthesis and antioxidant properties of (dodecylsulfanyl)methyl quercetin derivatives

Synthesis of heterocyclic analogs of isoflavone and homoisoflavone based on 3-formylchromone

“…Thus, Fitton and coworkers 67 suggested that the reaction of compound 1a with o-phenylenediamine in chloroform at room temperature aff orded benzodiazepinone 54, while Ghosh and Khan 68 assigned the Schiff base structure 55 to the product of this reaction in refl uxing EtOH. To the products obtained by oxidation of compound 54 with chloranil in refl uxing xylene 67 and heterocyclization of compound 55 in refl uxing AcOH, 68 the structure of benzo [b] chromeno-[2,3-e] [1,4]diazepin-13(6H)-one (56) was attributed. Later, Winkler and coworkers suggested 69 that the reaction of 1a with o-phenylenediamine gives dihydrotetraaza [14]annulene 57 and unambiguously confi rmed 70 this structure by X-ray diff raction analysis.…”

“…3-Formylchromones 1 reacted with 2 equiv. of thiobenzamide in refl uxing toluene to give 3-(5-phenyl-3H- [1,2,4]dithiazol-3-yl)chromones 82. 101 Under these acid under microwave irradiation conditions gave imidazo[1,2-a]pyridine isofl avone analogs 84 (Scheme 30).…”

“…[118][119][120] Diaminodihydropyridines 100 were the starting compounds for the synthesis of a large series of isofl avone hetero analogs. Thus, the reaction of compound 100c with acetic anhydride, ethyl formate, 6-chloro-3-formylchromone (1, R = 6-Cl), and chromone-3-carboxylic acid yielded [1,2,4] . 120 Ali and Ibrahim 120 examined antimicrobial activity of the synthesized compounds and found that the highest activity is exhibited by compounds 102-104.…”

“…Three-component condensation of 3-formylchromones 1, o-phenylenediamine, and 3-acetyl-4-hydroxycoumarin catalyzed by nano silica-supported N-propylsulfamic acid resulted in 4-hydroxy-3-[2-(4-oxo-4Hchromen-3-yl)-2,3-dihydro-1H-benzo[b] [1,4]diaze pin-4-yl]-2H-chromen-2-ones 151. 154 The use of dimed one as a CH acidic component gave rise to the fused 3,3-dimethyl-11-(4-oxo-4H-chromen-3-yl)-2,3,4,5,10,11-hexahydro-1H-dibenzo[b,e] [1,4]diazepin-1-ones 152. 155 The reaction requires no solvent and can be also catalyzed by silica-supported Fe(OTs) 3 .…”

“…One of the directions of this search is the modifi cation of natural biologically active substances. [1][2][3][4] From this viewpoint, 4H-chromen-4-one derivatives that are a subclass of fl avonoids, secondary metabolites of plants, are of great interest. The convenient precursors for the synthesis of heterocyclic analogs and homologs of isofl avones are 3-formylchromones (1) and, in particular compound 1a (R = H).…”