Substituted quinolinones 27.* Regioselective synthesis of pyrazolo-, oxazolo-, and triazepinoquinoline derivatives

First-principles density functional theoretical study on the structures, reactivity and spectroscopic properties of (NH) and (OH) Tautomer's of 4-(methylsulfanyl)-3[(1Z)-1-(2-phenylhydrazinylidene) ethyl] quinoline-2(1H)-one

“…Table 3 contains the complete data on NMR in enol, keto, and rotamer at B3LYP/6-31G(d,p) in comparison to experimental NMR. Figure 3 shows the calculated 13 C and 1 H NMR chemical shifts for 4-(methylsulfanyl)-3[(1Z)-1-(2 phenylhydrazinylidene) ethyl] quinoline-2(1H)-one in CHCl 3 agree well with the experimental results 8 . Table 3 shows that C 18 in the , in kcal/mol) for Keto → Enol (TS1) and Enol → Rotamer (TS2) conversions in gas phase and ethanol (in parentheses) using M06-2X energies.…”

“…Due to lack of data of 4-(methylsulfanyl)-3[(1Z)-1-(2-phenylhydrazinylidene) ethyl] quinoline-2(1H)-one and the compound is partially soluble in water and completely soluble in ethanol 8 . We present here a computational study on the structures, relative stabilities, and electronic absorption spectra of tautomeric forms of 4-(methylsulfanyl)-3[(1Z)-1-(2-phenylhydrazinylidene) ethyl] quinoline-2(1H)-one (Scheme 1) in the gas phase and ethanol at B3LYP with 6-31G(d,p), 6-311++G(2d,2p) basis sets, and M06-2X/6-311++G(2d,2p) level.…”

One-pot synthesis of 2,3-bis-(4-hydroxy-2-oxo-1,2-dihydroquinolin-3-yl)succinates and arylmethylene-bis-3,3′-quinoline-2-ones

“…2-Quinolones (Chen et al, 2001) have showed considerable interest because of their pharmacological importance (Abass et al, 2015) and various biological activities (Abass et al, 2005). Various quinolones are described to have antimicrobial (Eswaran et al 2010), antifungal ((Musiol et al, 2006), enzyme inhibitory (Slater et al, 1992) and cytotoxic activities (Ma et al, 2004).…”

Diphenylphosphoryl Azide (DPPA)‐Mediated One‐Pot Synthesis of Oxazolo[4,5‐c][1,8]naphthyridin‐4(5 H)‐ones, Oxazolo[4,5‐c]quinoline‐4(5 H)‐ones, and Tosyloxazol‐5‐yl Pyridines

“…During the past decade, severalroutes have been developed for the synthesis of functionalized fused oxazolo-quinolinone scaffolds, which typically relied on (i)cyclization of 3-amino-4hydroxy-2-quinolones with carboxylic acids/acid derivatives in polyphosphoric acid (PPA), [19] (ii)thermolysis of carboxylic acids with 4-azidoquinolones in PPA, [20] (iii)Beckmann rearrangement of the oxime of 3-aryl-4-hydroxy-2-quinolones, [21] (iv) reaction of a-isocyanoacetates with isatoic anhydrides, [22] (v) transitionmetal-catalyzed sequential reactiono fe thyl 2-chlorooxazole-4carboxylate, [23] (vi)cyclization of methyl 4-(methylthio)-2-oxo-1,2-dihydroquinoline-3-carboxylate with hydroxylamineh ydrochloridei ne thanol under reflux conditions, [24] and (vii)thermolysis of 3-amino-4-hydroxy-2-quinolone hydrochloride with triethylorthoformate (Scheme 1). [25] However, most of these approaches have one or more limitations such as the instability of startingm aterials or intermediates, relativelyh arsh reaction conditions, use of strong acidic media, which is incompatible with respect to functionality,p rolongedr eactiont imes, and most importantly use of preciousm etal catalysts, complex ligands,a nd toxic reagents, which adversely affect the environment.…”