Synthesis, crystal structure, and fungicidal activity of novel 1,5‐diaryl‐1H‐pyrazol‐3‐oxyacetate derivatives

Abstract

A series of ethyl 2-(1,5-diaryl-1H-pyrazol-3-yloxy)acetate derivatives (5a-5i) have been efficiently synthesized by the reaction of 1,5-diaryl-1H-pyrazol-3-ols (4a-4i) with ethyl 2-bromoacetate. The structures of the newly synthesized compounds were characterized by 1 H NMR spectra and elemental analysis, and the crystal structure of the compound ethyl 2-(5-(4-chlorophenyl)-1-phenyl-1H-pyrazol-3-yloxy)acetate (5c) was determined by single crystal X-ray diffraction analysis. The compound 5c belongs to triclinic system with space group P(-1), a

Crystal Structures, Vibrational Spectra, and Fungicidal Activity of 1,5-Diaryl-3-oxypyrazoles

“…Compounds I – IV were prepared from 1,5-diaryl-1 H -pyrazol-3-ols via a series of reactions that included substitution, hydrolysis, condensation, chlorination, glycosylation, or esterification [8,9,10,11,12].…”

“…Since the discovery of the fungicide pyraclostrobin by BASF scientists [1,2,3], aryloxypyrazoles have attracted enormous attention due to their diverse bioactivities in fungicide [4,5], insecticide [6], and herbicide [7]. We have also devoted considerable effort to develop this series of fungicide, and found several 1,5-diaryl-3-oxypyrazoles containing alkyloxyacetate, heterocycle, glucopyranosyl or benzoyl moieties with fungicidal activity [8,9,10,11,12]. However, their detailed structural properties and structure-activity relationship have not been reported.…”

Synthesis and Fungicidal Activity of Novel Chloro-Containing 1-Aryl-3-oxypyrazoles with an Oximino Ester or Oximino Amide Moiety

“…Our group has also devoted considerable effort to the development of novel fungicides. Bioactive (alkyl)oxyacetate, thiazolidine-2-thione, (O-acetyl)glucopyranosyl or benzoyl moieties were introduced into the 1-aryl-3-oxypyrazole structure of pyraclostrobin to replace its methoxycarbamate pharmacophore which could not be prepared in an environmentally friendly way, and some novel aryloxypyrazoles with good fungicidal activity were reported [9][10][11]. Furthermore, several biological studies have also indicated the 4-chloro-3-oxypyrazole moiety as a bioactive structure, and side chain modifications such as introduction of chlorine can indeed lead to a better fungicidal efficacy [12,13].…”

“…in CCl 4 as solvent, and with benzoyl peroxide (BPO) as catalyst. In our previous studies, we have prepared several ethyl 2-(1,5-diaryl-1H-pyrazol-3-yloxy)acetates by the substitution reaction of 1,5-diaryl-1H-pyrazol-3-ols with ethyl 2-bromoacetate in acetone, using potassium carbonate (K 2 CO 3 ) as acid-binding agent [11]. Motivated by this reaction, in our procedure, hydroxypyrazoles Ib and IIa-IId were allowed to react with benzyl bromide V in a 1:1.1 molar equiv.…”

Synthesis and bioactivity of novel 2-(1,2 benzisothiazol-3-yloxy)-N-(1-aryl-3-cyanopyrazol-5-yl) acetamides

“…Over the past years, N-arylpyrazole-containing heterocyclic scaffolds have been widely studied in many fields because of its diverse biological activities, such as antimicrobial, insecticide, and herbicidal. [1][2][3][4][5] Meanwhile, isothiazolone has attracted considerable interest because of its antimicrobial activity against bacteria and fungi. 6,7 Derivatives of isothiazolone also exhibit excellent performance as antibacterial and antifungal agents and enzyme inhibitors.…”