Synthesis and Biological Activity of New (E)-α-(Methoxyimino)benzeneacetate Derivatives Containing a Substituted Pyrazole Ring

Abstract

Strobilurins are one of the most important classes of agricultural fungicides. To discover new strobilurin analogues with high activity, a series of new strobilurin derivatives containing a substituted pyrazole in the side chain were synthesized and their biological activities were tested. The compounds were identified by (1)H nuclear magnetic resonance, infrared, and elemental analysis. The test results indicated that the compounds exhibited strong fungicidal activities against Pyricularia oryzae , Phytophthora infestans , Pseudoperonospora cubensis , and Erysiphe graminis . The relationship between structure and biological activity is discussed in terms of the effects of the substituents on the pyrazole ring. The present work demonstrates that strobilurin analogues with a 3-(substituted phenyl)-1H-pyrazol-5-oxy side chain can be used as possible lead compounds for the development of potential agrochemicals.

Morita–Baylis–Hillman adducts as building blocks of heterocycles: a simple approach to 4-substituted pyrazolones, and mechanism investigation via ESI–MS(/MS)

“…Here, we prepared the 2-methylated b-ketoesters observing no issues regarding dialkylation. Our protocol avoids the use of strong bases and acylating reagents and leads to both, yields and scope, comparable or even better than those reported in literature [27,29,32,33,[55][56][57][58][59][60]. This was clearly shown for compound 3b, where different methodologies and their respective yields are presented (Scheme 6) [27,29,33,[55][56][57].…”

Design, Synthesis and Fungicidal Activities of Some Novel Pyrazole Derivatives

“…The purification procedure of compounds 9-25 was recrystallization from isopropanol, the residue was purified through column chromatography using petroleum ether and ether as eluent to get products 1-8, 26 [34]. (5 Amino-3-(methylthio)-1-(2,4,6-trichlorophenyl) (9) (10 (11 (12 (14). Yield, 96%; white solid; m.p.…”

“…Compounds with pyrazole functional units exhibit antimicrobial [7], herbicidal [8], antitumor [9], insecticidal [10][11][12][13], fungicidal [14][15][16][17][18] and antiviral activities [19,20]. Lamberth [21] has summarized the significance of pyrazole derivatives in crop protection chemistry, including herbicidally-, fungicidally-and insecticidally-active pyrazole classes.…”

Design, Synthesis and Antifungal Activities of Novel Strobilurin Derivatives Containing Pyrimidine Moieties

“…[23][24][25][26] Utilizing the intermediate derivatisation method based on the active substructure combination and bioisosteric replacement, 27 a series of novel strobilurin derivatives containing pyrimidine moieties and strobilurin pharmacophore were designed and synthesized with the aim of obtaining more active candidates than the conventional azoxystrobin, hopefully against resistant fungal strains. The bioassays showed that most of the β-methoxyacrylate analogues exhibited potential antifungal activities against Colletotrichum orbiculare, Botrytis cinerea Pers and Phytophthora capsici Leonian.…”