64691-81-2Relevant academic research and scientific papers
Synthesis of arylhydrazone-based molecular switches using aryldiazonium silica sulfate nanocomposites and analysis of their isomerization
Abbaspourrad, Alireza,Aghaei, Hamidreza,Chermahini, Alireza Najafi,Khazdooz, Leila,Soltani, Solmaz,Zarei, Amin
, (2021/06/26)
A fast and efficient method for the synthesis of a series of arylhydrazones by reacting aryldiazonium silica sulfate nanocomposites with malononitrile, ethyl acetoacetate and dimedone is reported. All reactions were carried out in water at room temperature and the corresponding products were obtained in 77–87% yields. The existence of two kinds of intramolecular hydrogen bonds in the arylhydrazones synthesized using ethyl acetoacetate enables these compounds to be switched by rotation about the hydrazone C[dbnd]N bond, which leads to a reversible isomerization between their E and Z configurations. This switching can be controlled by changing the polarity of the solvents. The E/Z ratio of each synthesized compound was studied in CHCl3 and DMSO. The ratios of the E/Z were calculated using 1H NMR data in both CDCl3 and DMSO?d6, and used to calculate ΔG° for the E-Z isomerization of each synthesized compound in these two solvents. By changing the solvent from CHCl3 to DMSO, the E/Z ratios decreased. The results demonstrated that the ΔG° values for the formation of Z isomers were more negative than those of the E isomers in DMSO. This is why Z isomers are more stable than E isomers in DMSO. The results of density functional theory (DFT) calculations at B3LYP/6–311++G (d,p) level of theory, were in agreement with the experiments and confirmed the increased stability of Z isomers in DMSO. In most cases, DFT calculation in CDCl3 and DMSO indicate that the dipole moments of the Z isomers are significantly higher than those of the E isomers. Finally, the effect of temperature on the E-Z isomerization was studied using dynamic 1H NMR. The findings demonstrated that temperature does not have any significant effect on the E-Z isomerization in CDCl3 and DMSO?d6.
Effect of new carbonyl cyanide aromatic hydrazones on biofilm inhibition against methicillin resistant: Staphylococcus aureus
Lu, Jun,Lu, Xueer,Tang, Wenjian,Xu, Yingying,Zhang, Jing,Zhang, Ziwen
, p. 17854 - 17861 (2020/06/17)
Carbonyl cyanide m-chlorophenylhydrazone (CCCP), as a protonophore, in combination with antibiotics exhibited potentiating antibacterial activity. To improve CCCP's potency and toxicity, a series of aromatic hydrazones were synthesized and their antimicrobial activity was evaluated; amongst them, compounds 2e and 2j with a strong para-electron-withdrawing substituent (-NO2 and -CF3) at the phenyl ring had the lowest MICs against both S. aureus and methicillin resistant Staphylococcus aureus (1.56 and 1.56 μM, respectively). Some compounds in combination with antibiotics exhibited potentiate Gram-positive antibacterial activity; compound 2e was found to display unaided or synergistic efficacy against MRSA. In particular, when compound 2e is combined with ofloxacin, it has a good synergistic effect against MRSA. Moreover, electron microscopy revealed that compound 2e inhibits biofilm formation and effectively eradicates preformed biofilm. MTT assay showed that compound 2e displays as low toxicity as CCCP. Overall, our data showed that the aromatic hydrazone is a promising scaffold for anti-staphylococcal drug development.
Mechanically activated solid-state synthesis of phenylhydrazone derivatives via high-speed ball milling
Zhu, Xingyi,Chen, Yuanyuan,Chen, Yuhe,Wang, Jue,Su, Weike
, p. 621 - 626 (2014/07/21)
A series of phenylhydrazone derivatives was synthesized from arenediazonium tetrafluoroborates and active methylene compounds under high-speed ball milling. The reaction occurred in the absence of the solvent and products were obtained in good yield within short reaction times (no more than 30 min).
