Na-Bo Sun

Microwave Assisted Synthesis, Antifungal Activity and DFT Theoretical Study of Some Novel 1,2,4-Triazole Derivatives Containing the 1,2,3-Thiadiazole Moiety

In order to investigate the biological activity of 1,2,4-triazole compounds, seventeen novel 1,2,4-triazole derivatives containing 1,2,3-thiadiazole moieties were synthesized by multi-step reactions under microwave assisted conditions. The structures were characterized by 1H-NMR, 13C-NMR, MS and elemental analyses. The target compounds were evaluated for their in vivo fungicidal activities against Corynespora cassiicola, Pseudomonas syringae pv. Lachrymans, and Pseudoperonospora cubensis, and the results indicated that some of the title compounds displayed good fungicidal activities. Theoretical calculations on the title compounds were carried out at the B3LYP/6-31G (d,p). level. The full geometry optimization was carried out using the 6-31G(d,p) basis set, and the frontier orbital energy, atomic net charges were discussed, and the structure-activity relationships were also studied.

Design, Synthesis, DFT Study and Antifungal Activity of Pyrazolecarboxamide Derivatives

A series of novel pyrazole amide derivatives were designed and synthesized by multi-step reactions from phenylhydrazine and ethyl 3-oxobutanoate as starting materials, and their structures were characterized by NMR, MS and elemental analysis. The antifungal activity of the title compounds was determined. The results indicated that some of title compounds exhibited moderate antifungal activity. Furthermore, DFT calculations were used to study the structure-activity relationships (SAR).

Design, synthesis, antifungal activities and 3D-QSAR of new N,N'-diacylhydrazines containing 2,4-dichlorophenoxy moiety.

A series of new N,N′-diacylhydrazine derivatives were designed and synthesized. Their structures were verified by 1H-NMR, mass spectra (MS) and elemental analysis. The antifungal activities of these N,N′-diacylhydrazines were evaluated. The bioassay results showed that most of these N,N′-diacylhydrazines showed excellent antifungal activities against Cladosporium cucumerinum, Corynespora cassiicola, Sclerotinia sclerotiorum, Erysiphe cichoracearum, and Colletotrichum orbiculare in vivo. The half maximal effective concentration (EC50) of one of the compounds was also determined, and found to be comparable with a commercial drug. To further investigate the structure–activity relationship, comparative molecular field analysis (CoMFA) was performed on the basis of antifungal activity data. Both the steric and electronic field distributions of CoMFA are in good agreement in this study.

3-[(3-Ethyl-1-methyl-4-nitro-1H-pyrazol-5-yl)carbonyl]-1H-benzimidazole

In the title compound, C14H13N5O3, the dihedral angle formed between the five-membered pyrazole and the benzimidazole ring system is 68.2 (2)°.

2‐(4,6‐Dimethoxy­pyrimidin‐2‐yl­oxy)‐6‐fluoro‐N‐(3‐methyl­pyrid­yl)benzyl­amine

In the title compound, C19H19FN4O3, the two heterocyclic ring substituents lie on the same side of the central benzene ring.