Synthesis of N1-arylidene-N2-quinolyl- and N2-acrydinylhydrazones as potent antimalarial agents active against CQ-resistant P. falciparum strains

Synthesis, Molecular Modeling, and Quantitative Structure–activity Relationship Studies of Undec-10-Enehydrazide Derivatives as Antimicrobial Agents

“…The presence of two singlet peaks for NH and NH 2 at δ 3.88 ppm and δ 7.49 ppm, respectively, revealed the formation of undec-10-ene hydrazide 3. The appearance of singlet signal ranging from δ 7.49 to 10.72 ppm in the synthesized compounds (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16) confirmed the presence of NH of hydrazide derivatives. The appearance of singlet signal of CH proton in compounds 5 at δ 7.92 ppm revealed the formation of N=CH bond in the synthesized derivative.…”

“…The presence of the C=C str. aromatic was indicated by the appearance of a stretching band around 1600 cm , which is the characteristics of azetidinones (16). Further, the appearance of IR band around 3200-3300 cm −1 showed the presence of NH linkage of azetidinone ring.…”

“…The methyl ester 2 was refluxed with hydrazine hydrate to yield undec-10-ene hydrazide 3, which was condensed with corresponding aromatic aldehydes/acetophenone to synthesize the target undec-10-ene hydrazide derivatives (4-13). Then, corresponding undec-10-enehydrazide derivatives (4-6) was refluxed with chloroacetyl chloride and triethylamine in dioxane to produce azetidinone derivatives (14)(15)(16). The undec-10-ene hydrazide 3 was also reacted with ethyl acetoacetate; acetic acid in acetic anhydride and acetic anhydride to yield…”

“…The synthesis of the intermediate (2,3) and target compounds (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19) was performed according to reactions outlined in Schemes 1 and 2. A methanolic solution of undecylenic acid 1 was refluxed in the presence of sulfuric acid to yield the methyl ester undecylenic acid (2).…”

“…Further, the previous studies performed by us revealed the significance of different acid derivatives, including undec-10-enoic hydrazide-hydrazone derivatives as antibacterial and antifungal agents [6][7][8][9][10][11]. Studies reported by various research groups also showed that hydrazide-hydrazone derivatives of different acids have wide range of biological activities, viz., antibacterial [12], antifungal [13], antitubercular [14], trypnocidal [15], antimalarial [16], antiviral [8], anti-inflammatory [17], and antitumor [18] activities. Isoniazid (antitubercular) [19], nifuroxazide (antidiarrheal and antitumor) [20], nifurtimox (antiamoebic) [21], furacin (antibiotic) [22], and furazolidone (antibacterial) [23] are hydrazide containing important biologically active drug molecules.…”