Synthesis,structure and biological activity studies of 2‐[(1H‐1,2,4‐triazol‐1‐yl)methyl]‐1‐aryl)‐3‐ferrocenyl prop‐2‐en‐1‐one derivatives

Fifteen new ferrocene derivatives containing 1H‐1,2,4‐triazole moiety were synthesized in various yields by the condensation of ferrocenecarboxaldehyde with 1‐aryl‐3‐(1H‐1,2,4‐triazo‐1‐yl)‐propen‐1‐ones in toluene. Their structures have been confirmed by ¹H NMR, IR, MS and elemental analysis. In addition, the crystal structure of 4l was determined. The antifungal and plant growth regulatory activities of the title compounds are discussed. Copyright © 2005 John Wiley & Sons, Ltd.     

Synthesis,Antimicrobial, and Brine Shrimps Lethality Assays of 3,3‐Diaryl‐4‐(1‐methyl‐1H‐indol‐3‐yl)azetidin‐2‐ones

The paper describes the synthesis, characterization data, and biological activity (antibacterial, antifungal, and brine shrimps lethality) of new azetidin‐2‐ones. The compounds have been synthesized by the reaction of diarylketenes, generated in situ from thermal decomposition of the 2‐diazo‐1,2‐diarylethanones, with N‐(1‐methyl‐1H‐indol‐3‐yl)methyleneamines. The compounds have been characterized by elemental analysis and spectral (IR, ¹H and ¹³C NMR, and MS) data. The paper also reports the results of antibacterial, antifungal, and brine shrimps lethality assays of these compounds. Some of the compounds exhibited significant biological activity.     

Synthesis,Dissociation Constants,and Antimicrobial Activity of Novel 2,3‐Disubstituted‐1,3‐thiazolidin‐4‐one Derivatives

In this article, a new series of 2,3‐disubstituted‐1,3‐thiazolidin‐4‐one derivatives have been designed, synthesized, and evaluated as antimicrobial agents. New compounds were prepared by the cyclization reaction of N‐substituted carboxylic acid hydrazide derivatives with mercaptoacetic acid. The structures of the obtained compounds were confirmed by means of IR, ¹H NMR, and ¹³C NMR spectra. The dissociation constants were determined using spectrophotometric method. All synthesized compounds were tested for their in vitro antibacterial and antifungal activities using the broth microdilution method.     

Design,Synthesis, and Antifungal Activity of 3‐(Thiophen‐2‐yl)‐1,5‐dihydro‐2H‐pyrrol‐2‐one Derivatives Bearing a Carbonic Ester Group

A series of 3‐(thiophen‐2‐yl)‐1,5‐dihydro‐2H‐pyrrol‐2‐one derivatives bearing a carbonic ester group were designed and synthesized by integrating a thiophene nucleus and a pyrroline‐2‐one scaffold in a single molecular architecture. Their structures were confirmed by IR, ¹H‐NMR, EI‐MS, and elemental analyses, and their antifungal activities against Fusarium graminearum (Fg), Rhizoctorzia solani (Rs), and Botrytis cinerea (Bc) were evaluated. The antifungal bioassays indicated that some title compounds exhibited desirable antifungal effects against the tested fungi. Strikingly, the title compounds 4i , 4k , 4n , and 4o showed obvious antifungal activities against Rs, with corresponding EC₅₀ values of 35.26, 33.56, 23.90, and 30.48 μg/mL, respectively, which are better than that of hymexazol (37.86 μg/mL). These results indicated that 3‐(thiophen‐2‐yl)‐1,5‐dihydro‐2H‐pyrrol‐2‐one derivatives bearing a carbonic ester group can serve as potential structural templates in the search for novel high‐efficient fungicides.     

Design,Synthesis, Antifungal Activities and SARs of (R)‐2‐Aryl‐4,5‐dihydrothiazole‐4‐carboxylic Acid Derivatives

Based on the structure of natural product 2‐aryl‐4,5‐dihydrothiazole‐4‐carboxylic acid, a series of novel (R)‐2‐aryl‐4,5‐dihydrothiazole‐4‐carboxylic acid derivatives were designed and synthesized. Their structures were characterized by ¹H NMR, ¹³C NMR and HRMS. The single crystal structure of compound 9b was determined by X‐ray diffraction analysis. The antifungal activities were evaluated for the first time. The bioassay results indicated that most compounds exhibited moderate to good antifungal activities. The antifungal activities of compound 13a (against Cercospora arachidicola Hori), 13d (against Alternaria solani), and 16e (against Cercospora arachidicola Hori) were 61.9%, 67.3% and 61.9%, respectively, which are higher than those of the commercial fungicides chlorothalonil and carbendazim. Moreover, compound 13d exhibited excellent antifungal activities against 7 kinds of the fungi tested (66.7%, 77.3%, 63.0%, 87.9%, 70.0%, 70.0% and 80.0% at 50 µg?mL). Therefore, 13d can be used as a new lead structure for the development of antifungal agents.     

Novel Approach for Rapid and Efficient Synthesis of 2‐(3‐(4‐Aryl)‐1‐isonicotinoyl‐4,5‐dihydro‐1H‐pyrazol‐4‐yl)‐3‐phenylthiazolidin‐4‐one Derivatives and Screened Their Antimicrobial Activity

A series of compounds, viz. 2‐(3‐(4‐aryl)‐1‐isonicotinoyl‐4,5‐dihydro‐1H‐pyrazol‐4‐yl)‐3‐phenylthiazolidin‐4‐one 4 ( a – n ), have been synthesized by reaction of 3 ( a – n ) with thioglycolic acid in the presence of zinc chloride. Compounds 3 ( a – n ) have been synthesized by amination of formylated pyrazoles 2 ( A – B ), which were synthesized by formylation of 1 ( A – B ) by Vilsmeier–Haack reagent (POCl₃/DMF). Compounds 1 ( A – B ) were synthesized by condensation of hydrazide and substituted acetophenones under conventional method and microwave irradiation method. These compounds were identified on the basis of melting point range, Rf values, infrared, ¹H NMR, and mass spectral analysis. These compounds were evaluated for their in vitro antimicrobial activity, and their minimum inhibitory concentration was determined. Among them, compound 4b and compound 4l possess appreciable antimicrobial and antifungal activities. Antibacterial activity results showed that compounds containing electron‐withdrawing groups were more active than compounds containing electron‐releasing groups.     

Synthesis and Bioactivities of Novel 1‐(3‐Chloropyridin‐2‐yl)‐N‐Substituted‐5‐(Trifluoromethyl)‐Pyrazole Carboxamide Derivatives

A series of novel 1‐(3‐chloropyridin‐2‐yl)‐N‐substituted‐5‐(trifluoromethyl)‐pyrazole carboxamide derivatives TC₁ , TC₂ , TC₃ , TC₄ , TC₅ , TC₆ , TC₇ , TC₈ , TC₉ , TC₁₀ , TC₁₁ were synthesized and characterized by IR, ¹H NMR, ¹³C NMR, MS, and elemental analysis. All the target compounds were tested in vitro for their antibacterial activities and antifungal activities. The preliminary bioassays indicated that compound TC₆ exhibited excellent activity against Xanthomonas oryzae (94.9% and 84.9%) at different concentrations (200 µg/mL and 100 µg/mL), which was higher than that of Bismerthiazol (94.6% and 64.0%), respectively. At the same time, most of the compounds exhibited moderate antifungal activities against four kinds of phytopathogenic fungi     

Design,Synthesis, and Antifungal Activities of New β‐Methoxyacrylate Analogues

Strobilurins have become one of the most important classes of agricultural fungicides. To search for new strobilurin derivatives with high activity against resistant pathogens, a series of new β‐methoxyacrylate analogues containing substituted pyrimidine in the side chain with strobilurin pharmacophore were synthesized and their biological activities were tested. The compounds were confirmed and characterized by ¹H‐NMR, elemental analysis and mass spectroscopy. The bioassays indicated that most of the compounds 1 exhibited potent antifungal activities against Colletotrichum orbiculare, Botrytis cinerea Pers and Phytophthora capsici Leonian at a concentration of 50 μg mL^?1. Notably, compound 1b (R = 2,5‐dimethylphenyl) showed better antifungal activity against all the tested fungi than the commercial strobilurin fungicide azoxystrobin.     

Synthesis,spectral, and antimicrobial studies of 1‐butyl‐3‐substituted‐4‐(2‐aryl‐1H‐indol‐3‐yl)‐2‐azetidinones

Ketene generated from acetyl chloride or chloroacetyl chloride adds on indolyl Schiff's base double bond to afford 1‐butyl‐3‐substituted‐4‐(2‐aryl‐1H‐indol‐3‐yl)‐2‐azetidinones in THF. The reaction proceeds stereospecifically via concerted trans [2+2] cycloaddition. The synthesized compounds have been characterized by elemental analyses and spectral data (IR, PMR, and mass). All synthesized compounds have been evaluated for antibacterial and antifungal activities, and 4g to 4l have shown promising results. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:494–501, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20052     

Synthesis and Evaluation of Antimicrobial Activity of Some New Hetaryl‐Azoles Derivatives Obtained from 2‐Aryl‐4‐methylthiazol‐5‐carbohydrazides and Isonicotinic Acid Hydrazide

A series of new 1,3,4‐oxadiazole/thiadiazole and 1,2,4‐triazole derivatives have been synthesized starting from 2‐aryl‐4‐methylthiazol‐5‐carbohydrazides and isonicotinic acid hydrazide. All the newly synthesized compounds were characterized by IR, ¹H NMR, ¹³C NMR, and mass spectrometry. The synthesized compounds were screened for their antibacterial and antifungal activity, assessed as growth inhibition diameter. Some of them showed good antibacterial activity against gram positive Staphylococcus aureus, while the antibacterial activity against Listeria monocytogenes, Escherichia coli, and Salmonella typhymurium and antifungal activity against Candida albicans was modest. None of the tested compounds showed inhibitory activity against gram positive bacteria Enterococcus faecalis and Bacillus cereus and against gram negative bacteria Pseudomonas aeruginosa.     

Synthesis and Antifungal Activity of Novel 1,2,4‐Triazole Derivatives Containing 1,2,3‐Thiadiazole Moiety

Starting from carbonic acid diethyl ester, a series of 1,2,4‐triazole derivatives containing 1,2,3‐thiadiazole were synthesized. Reactions were performed by microwave irradiation or ultrasonic irradiation as well as by conventional heating. The structure of title compounds was characterized by ¹H‐NMR, MS, and elemental analyses. The fungicidal activities of these compounds were tested in vivo. Most of title compounds exhibited good antifungal activity against Pseudoperonospora cubensis. Some of title compounds displayed moderate antifungal activities against Fusarium oxysporum, Pseudoperonospora cubensis, Sphaerotheca fuligenea, Corynespora cassiicola, and Xanthomonas axonopodis.     

Synthesis and antimicrobial activity of some 7‐aryl‐5,6‐dihydro‐14‐aza[1]benzopyrano[3,4‐b]phenanthren‐8H‐ones

The title compounds, 7‐aryl‐5,6‐dihydro‐14‐aza[1]benzopyrano[3,4‐b]phenanthren‐8H‐ones 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h , 3i , 3j , 3k , 3l have been synthesized by reacting various 4‐hydroxy coumarins 1a , 1b , 1c with 2‐arylidene‐1‐tetralones 2a , 2b , 2c , 2d in the presence of ammonium acetate and acetic acid under Krohnke's reaction condition. The structures of all the synthesized compounds were supported by analytical, IR, ¹H‐NMR, and ¹³C‐NMR data. All the synthesized compounds 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h , 3i , 3j , 3k , 3l have been screened for their antibacterial activities against Escherichia coli (Gram ?ve bacteria), Bacillus subtilis (Gram +ve bacteria), and antifungal activity against Candida albicans (Fungi). J. Heterocyclic Chem., (2011).     

Synthesis and Pharmacological Evaluation of a Novel Series of 2‐((2‐Aryl thiazol‐4‐yl)methyl)‐5‐(alkyl/alkylnitrile thio)‐1,3,4‐oxadiazole Derivatives as Possible Antifungal Agents

In the present investigation, a novel series of 2‐[(2‐arylthiazol‐4‐yl)methyl]‐5‐(alkyl/alkylnitrile thio)‐1,3,4‐oxadiazole derivatives were synthesized by cyclo‐condensation of 2‐(2‐substituted thiazol‐4‐yl)aceto hydrazide with carbon disulfide followed by S‐alkylation with alkyl halide in dry acetone. All the newly synthesized compounds were characterized by spectral (IR, ¹H NMR, ¹³C NMR, mass, and elemental analysis) methods. The title compounds were screened for in vitro antifungal activity and most of the synthesized compounds show moderate to good antifungal activity.     

Synthesis and Evaluation of Novel 5‐cyclohexyl‐2‐(4″‐substitutedphenyl)‐3‐(2″‐substitutedphenyl)4H‐2,3,3a,5,6,6a‐hexahydropyrrolo[3,4‐d]isoxazole‐4,6‐dione Derivatives for Their In Vitro Antioxidant and Antibacterial Activities

1,3‐Dipolar cycloaddition reactions of N‐cyclohexyl maleimide ( 1 ) with azomethine N‐oxide ( 2 ) have afforded novel isoxazolidine ( 3 ) in excellent yield. Their structures have been characterized from their IR, ¹H‐NMR, ¹³C‐NMR, ¹H,¹H‐COSY, MS(ESI), and elemental analysis techniques. In vitro antibacterial activity of the synthesized compounds were investigated against a representative panel of pathogenic strains specifically two Gram‐positive bacteria (Staphylococcus aureus and Streptococcus pyogenes ) and two Gram‐negative bacteria (Pseudomonas aeruginosa and Escherichia coli ) using agar‐well diffusion assay. Some of the compounds ( 3a , 3k , 3n , and 3o ) exhibited promising antibacterial activities. All the synthesized compounds have also been screened for their antioxidant activities and were found to be significantly active.     

Synthesis and Antimicrobial Activity of 2‐(Pyridine‐3‐yl)‐4H‐chromen‐4‐one Derivatives

An efficiently synthesis of chromones via cyclodehydration of corresponding 1‐(2‐hydroxyphenyl)‐3‐(pyridine‐3‐yl)propane‐1,3‐dione is described under ultrasound irradiation. A series of novel 2‐(pyridine‐3‐yl)‐4H‐chromen‐4‐one derivatives was confirmed on the basis of ¹H‐NMR, mass, IR spectral data, and elemental analysis. The synthesized compounds were evaluated for their antibacterial and antifungal activities. Most of the compounds were found to be comparable potent than the reference standard drugs. Utilization of ultrasound irradiation, simple reaction conditions, isolation, and purification makes this manipulation very interesting from an economic and environmental perspective.     

Synthesis of Novel 1‐(5‐(Benzylsulfinyl)‐3‐methyl‐1,3,4‐thiadiazol‐2(3H)‐ylidene)‐thiourea/urea Derivatives and Evaluation of Their Antimicrobial Activities

A new series of 1‐(5‐(benzylsulfinyl)‐3‐methyl‐1,3,4‐thiadiazol‐2(3H)‐ylidene)‐thiourea/urea derivatives ( 1a – j ) were designed and synthesized. For the first time, (i) a new process was developed for N‐methylation of 1,3,4‐thiadiazole moiety using dimethyl carbonate an environmentally benign reagent in presence of N,N,N′,N′‐tetramethylethylenediamine and (ii) the sulfide was selectively oxidized to sulfoxide in higher yield by using chlorine (g) in aqueous acetic acid media under mild reaction condition. The synthesized compounds ( 1a – j ) were investigated for their antimicrobial activities. The tested compounds ( 1a – j ) were exhibited moderate to excellent antibacterial activities against both Gram‐positive and Gram‐negative bacterial strains. The same compounds exhibited good antifungal activities against selected fungal strains. Particularly, the compounds 1b , 1d , 1h , and 1i were proved to be promising leads exhibiting both antibacterial and antifungal activities compared with standard drugs, ciprofloxacin, and fluconazole. The presence of 1,3,4‐thiadiazole moiety has a significant role in the display of antimicrobial activity. In addition, the presence of both sulfinyl and thiourea or urea functionalities has enhanced the activity as per obtained antimicrobial activity data.     

Synthesis and Antifungal Activity of Novel Chiral α-Aminophosphonates Containing Fluorine Moiety

Chiral α-aminophosphonates were synthesized using （R） or （S）-1-phenylethylamine in the presence of BF3·Et2O under microwave irradiation in moderate to good yields. The new compounds were identified by ^1H NMR, ^19F NMR, IR and elemental analysis. Their antifungal activities were evaluated and some compounds were found to exhibit excellent antifungal activities. To the best of our knowledge, this is the first report on antifungal activity of chiral α-aminophosphonates containing fluorine moiety.     

Synthesis and antimicrobial activities of new 4,6‐diaryl‐ 4,5‐dihydro‐3‐hydroxy‐2H‐indazoles

A series of new 4,6‐diaryl‐4,5‐dihydro‐3‐hydroxy‐2H‐indazoles 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j , 5k were synthesized by the cyclization of ethyl 2‐oxo‐4,6‐diarylcyclohex‐3‐ene carboxylates 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i , 4j , 4k . The compounds were characterized by IR, ¹H NMR, ¹³C NMR, 2D NMR, and elemental analysis. The synthesized compounds were evaluated for in vitro antibacterial and antifungal activities against Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa, Candida albicans, Aspergillus niger, Aspergillus flavus, and Rhizopus sp. Most of the compounds exhibited good activity against the tested organisms. J. Heterocyclic Chem.,, (2012).     

Synthesis and antimicrobial activity of N‐substituted N′‐[6‐methyl‐2‐oxido‐1,3,2‐dioxaphosphinino(5,4‐b)pyridine‐2‐yl]ureas

N‐Substituted N′‐[6‐methyl‐2‐oxido‐1,3,2‐dioxaphosphinino(5,4,‐b)pyridine‐2‐yl]ureas have been accomplished by condensation of equimolar quantities of chlorides of various carbamidophosphoric acids ( 3 ) with 3‐hydroxyl‐6‐methyl‐2‐pyridinemethanol (lutidine diol) ( 4 ) in the presence of triethylamine in dry toluene–tetrahydrofuran (1:1) mixture at 45–50°C. Their structures were established by elemental analyses, IR, ¹H NMR, ¹³C NMR, and ³¹P NMR spectral data. Their antifungal and antibacterial activity is also evaluated. Most of these compounds exhibited moderate antimicrobial activity in the assays. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:509–512, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10181     

Synthesis and Biological Activity of Some Novel Aryl‐Substituted 1,3,4‐Oxadiazole Mannich Bases Containing Pyrimidine Rings

A series of novel Mannich base derivatives (E₁–E₁₅) of 5‐aryl‐1,3,4‐oxadiazole‐2‐thione with substituted pyrimidine were synthesized and characterized by elemental analysis, IR, ¹H‐NMR. The antifungal activities of these compounds were also originally studied. The results showed that most of the title compounds exhibited relatively good fungicidal activities. Especially compounds E₈ and E₁₃ showed better antifungal activity than comparison compound hymexazol. The relationship of structure and activity revealed that the presence of the methyl group at four and six positions of pyrimidine ring remarkably enhanced the antifungal activity of title compounds.