Synthesis and Antimicrobial Studies of Novel Billogical Heterocycles

The synthetic route of sildenafil promoted us to synthesize new object molecules. New analogues containing a 4-thiazolidinone ring bonded to the phenyl moiety at the 2-position, 7-(substituted anilino)-6-fluoro-2-(p-meth- oxy-m-{[2-(p-hydroxyphenyl)-4-oxo-1,3-thiazolidin-3-yl]aminocarbonyl}phenylsulfonamido)benzothiazoles (4a—4l) have been synthesized by cyclization with thioglycollic acid of Schiff bases 3a—3l from corresponding 7-(substituted anilino)-6-fluoro-2-(p-methoxy-m-hydrazinocarbonyl phenylsulfonamido)benzothiazoles (2a—2l). Compounds 2a—2l in turn were prepared by dehydroxyhalogenation followed by condensation with hydrazine hydrates of acids 1a—1l. Compounds 1a—1l in turn were prepared by chlorosulfonation of o-methoxy benzoic acid followed by condensation with 6-fluoro-7-(substituted anilino)-2-aminobenzothiazoles. Final compounds have been characterized by their elemental analysis, IR, NMR and mass spectra. All the synthesized compounds have been screened for their antimicrobial activities. Some of them showed good activities.     

Design,Synthesis and Antitumor Activity of Asymmetric Bis(s‐triazole Schiff‐base)s Bearing Functionalized Side‐Chain

1‐Amino‐2‐pyrid‐3‐yl‐5‐(2‐benzoylethylthio)‐s‐triazole ( 1 ) was condensed with 1‐amino‐3‐mercapto‐5‐ [(un)substituted phenyl]‐s‐triazoles and subsequently substituted with chloroacetic acid to afford bis‐s‐triazole sulfanylacetic acid mono‐Schiff bases ( 3a – 3e ), which were condensed with 9‐formylanthracene to produce asymmetric bis(s‐triazole Schiff base) sulfanylacetic acids ( 4a – 4e ). The structures of new synthesized compounds were characterized by elemental analysis and spectral data, and their in vitro antitumor activity against L1210, CHO and HL60 cell lines was evaluted via the respective IC₅₀ values by methylthiazole trazolium (MTT) assay.     

Facile Synthesis of Novel 3‐(4‐phenylisothiazol‐5‐yl)‐2H‐chromen‐2‐one Derivatives as Potential Anticancer Agents

A series of 3‐(4‐phenylisothiazol‐5‐yl)‐2H‐chromen‐2‐one ( 6a – l ) derivatives has been efficiently synthesized by straightforward sequential reactions. Tandem Vilsmeier Hack reaction/cyclization/bromination/Suzuki cross‐coupling reactions were successfully applied to the preparation of title compounds in good‐to‐high yields. In the synthetic sequences, 3‐chloro‐3‐(2‐oxo‐2H‐chromen‐3‐yl)acrylaldehydes ( 2 ) were found to react with ammonium thiocyanate to yield the corresponding 3‐(isothiazol‐5‐yl)‐2H‐chromen‐2‐ones ( 3 ). These derivatives were brominated with N‐bromo succinamide to yield the corresponding regioselective 3‐(4‐bromoisothiazol‐5‐yl)‐2H‐chromen‐2‐one ( 4 ). Finally, compound 4 was treated with various phenyl/pyrazole/7H –pyrrolo[2,3‐d]pyrimidinyl boronic acids 5a – l in the presence of K₂CO₃ and Pd catalyst in dimethylformamide to yield the corresponding title derivatives 6a – l . All the synthesized compounds were characterized by analytical and spectral studies. All the final compounds were screened against different cancer cell lines (A549, PC3, SKOV3, and B16F10), and among these compounds, 6b , 6g , 6h , and 6l displayed moderate cytotoxic activity against the tested cell lines.     

An Expedient Synthesis of Novel N,N′‐Diglycosylguanidine Derivatives in the Presence of Hg(II)

The reactions of N,N′‐diglycosythiourea with 2‐amino‐benzothiazoles in the presence of Hg(II) (HgCl₂ or HgO) for the synthesis of N‐(4/6‐substituted‐benzothiazol‐2‐yl)‐N′,N″‐diglycosylguanidines have been reported.     

Highly Efficient [3 + 2] Cycloaddition: Click Synthesis of Novel 1H‐indol‐3‐yl‐benzo[d]imidazole Bis‐triazoles

A series of novel 1‐((1H‐1,2,3‐triazol‐4‐yl)methyl)‐2‐(1‐((1H‐1,2,3‐triazol‐4‐yl)methyl)‐5‐substituted‐1H‐indol‐3‐yl)‐6‐substituted‐1H‐benzo[d]imidazoles 5a – i have been prepared using click chemistry as an ideal strategy where [3 + 2] cycloaddition of azides with terminal alkynes has been developed as the target compounds. In route‐II, 5‐substituted‐1H‐indole‐3‐carbaldehydes 1a – c react with 5‐substituted orthophenylenediamine 8 to give desired products, that is, 6‐substituted‐2‐(5‐substituted‐1H‐indol‐3‐yl)‐1H‐benzo[d]imidazole 6a – i . Here, 6a – i react with 2 equiv of propargylbromide 7 to give novel 6‐substituted 2‐(5‐substituted‐1‐(prop‐2‐yn‐1‐yl)‐1H‐indol‐3‐yl)‐1‐(prop‐2‐yn‐1‐yl)‐1H‐benzo[d]imidazole 4a – i . 4a – i were reacted with 2 equiv of NaN₃ in t‐butanol/water (1:2) and add catalytic amount of CuSO₄.5H₂O. Stir the reaction mixture at room temperature to get the target products 5a – i . Here, obtained products contain four rings, that is, one indole, two triazoles, and one benzimidazole. The main advantages of this method are short reaction times, easy workup, higher yields (88–92%), and no by‐products formation.     

Synthesis of Some New Pyridine and Pyrimidine Derivatives Containing Benzothiazole Moiety

A variety of pyridine and pyrimidine rings incorporating benzothiazole moiety were synthesized by reaction of 1‐(2‐benzothiazolyl)‐1‐cyano‐3‐chloroacetone ( 1 ) with 2‐pyridone, 2‐thioxopyridine, thiouracil, and 2‐thioxopyrimidine derivatives to give compounds 7,9‐dimethylfuro[2,3‐b:4,5‐b′]dipyridin‐4‐ol 5 , 4, 6‐diphenylthieno[2,3‐b]pyridin‐2‐yl 9 , 2‐(benzo[d]thiazol‐2‐yl)‐2‐(7‐substituted‐5‐oxo‐5H‐thiazolo[3,2‐a]pyrimidin‐3‐yl)acetonitriles 12a and 12b , pyrimido[2,1‐b][1,3]thiazepine‐3‐carboxamide 15 , and benzo[4,5]thiazolo[3,2‐b]pyridazine‐3‐one 20 , respectively.     

Synthesis of Some New 2‐Oxo‐N‐[(10H‐phenothiazin‐10‐yl)alkyl] Derivatives of Azetidine‐1‐carboxamides

The synthesis of a new series of 4‐aryl‐3‐chloro‐2‐oxo‐N‐[3‐(10H‐phenothiazin‐10‐yl)propyl]azetidine‐1‐carboxamides, 4a – 4m , is described. Phenothiazine on reaction with Cl(CH₂)₃Br at room temperature gave 10‐(3‐chloropropyl)‐10H‐phenothiazine ( 1 ), and the latter reacted with urea to yield 1‐[3‐(10H‐phenothiazin‐10‐yl)propyl]urea ( 2 ). Further reaction of 2 with several substituted aromatic aldehydes led to N‐(arylmethylidene)‐N′‐[3‐(phenothiazin‐10‐yl)propyl]ureas 3a – 3m , which, on treatment with ClCH₂COCl in the presence of Et₃N, furnished the desired racemic trans‐2‐oxoazetidin‐1‐carboxamide derivatives 4a – 4m . The structures of all new compounds were confirmed by IR, and ¹H‐ and ¹³C‐NMR spectroscopy, FAB mass spectrometry, and chemical methods.     

Synthesis of Some Novel Phenyl Substituted Oxothiazolidin- 1’’,3’’,4’’-thiadiazolo-[3’,4’-b]thiazoline of 3β-Substituted Cholestane

Three title compounds 4a—4c have been synthesized by the cyclodehydration of 1’-benzylidine-4’-(3β-substituted-5α-cholestane-6-yl)thiosemicarbazones 2a—2c with thioglycolic acid followed by the treatment with cold conc. H2SO4 in dioxane. The compounds 2a—2c were prepared by condensation of 3β-substituted-5α-cholestan- 6-one-thiosemicarbazones 1a—1c with benzaldehyde. These thiosemicarbazones 1a—1c were obtained by the reaction of corresponding 3β-substituted-5α-cholestan-6-ones with thiosemicarbazide in the presence of few drops of conc. HCl in methanol. The structures of the products have been established on the basis of their elemental, analytical and spectral data.     

Heterocyclic synthesis: A convenient route to some 2‐mercepto 1,3,4‐oxadiazole and green chemistry microwave‐induced one‐pot synthesis of 2‐aryl 1,3,4‐oxadiazole in quinazolone and their antibacterial and antifungal activity

Several 6‐substituted‐3‐[(5‐mercepto‐1,3,4‐oxadiazol‐2‐yl)methyl]‐2‐substituted quinazolin‐4(3H)‐one or 6‐substituted‐3‐[4‐(5‐mercepto‐1,3,4‐oxadiazol‐2‐yl)phenyl]‐2‐substituedquinazolin‐4(3H)‐one 2(a‐l) and 6‐substituted‐3‐[(5‐phenyl‐1,3,4‐oxadiazol‐2‐yl)methyl]‐2‐substitutedquinazolin‐4(3H)‐one or 6‐substi‐tuted‐3‐[4‐(5‐phenyl‐1,3,4‐oxadiazol‐2‐yl) phenyl]‐2‐substitutedquinazolin‐4(3H)‐one 3(a‐l) were synthesized using conventional and microwave techniques respectively and were screened for antibacterial and antifungal activity.     

Purines. Part XVI

A series of N‐substituted 8‐aminoxanthines (=8‐amino‐3,7(or 3,9)‐dihydro‐1H‐purine‐2,6‐diones) 8 – 16 and 34 – 37 were synthesized from the corresponding 8‐nitroxanthines 1 – 7, 30 – 33 , and 8‐(phenylazo)xanthines 17 and 18 by catalytic reduction. Another approach was derived from 6‐amino‐5‐(cyanoamino)uracils (=N‐(6‐amino‐1,2,3,4‐tetrahydro‐2,4‐dioxopyrimidin‐5‐yl)cyanamides) 23, 24 , and 27 by base‐catalyzed cyclization yielding 25 – 28 . All 8‐aminoxanthines 8 – 29 and 34 – 37 were acetylated to the corresponding 8‐(acetylamino)xanthines 40 – 57 , and prolonged heating led to 8‐(diacetylamino)xanthines 58 and 59 . Several 8‐aminoxanthines 8 – 13 were diazotized forming 8‐diazoxanthines 60 – 64 . Coupling reactions of isolated 62 and 64 and intermediary formed 8‐diazoxanthines with 1,3‐dimethylbarbituric acid (=1,3‐dimethylpyrimidine‐2,4,6(1H,3H,5H)‐trione; 66 ) resulted in 5‐[(xanthin‐8‐yl)diazenyl]‐1,3‐dimethylbarbituric acids=3,7(or 3,9)‐dihydro‐8‐[2‐(1,2,3,4‐tetrahydro‐1,3‐dimethyl‐2,4‐dioxopyrimidin‐5‐yl)diazenyl]‐1H‐purine‐2,6‐diones) 67 – 80 . The newly synthesized xanthine derivatives were characterized by the determination of their pK_a values, the UV‐ and NMR spectra, as well as elemental analyses.     

Regioselective Synthesis and Antibacterial Activity Studies of 1,2,3‐Triazol‐4‐YL]‐4‐methyl‐2H‐chromen‐2‐ones

Synthesis, spectral analysis, and antibacterial activity of new coumarin derivatives are described in this paper. Twelve new coumarin derivatives were synthesized in moderate to good yields by the react with 4‐methyl‐6‐(prop‐2‐ynyloxy)‐2H‐chromen‐2‐one ( 3a – c ) and ethyl azide ( 4a – l ) and done by the click reaction to obtained 6‐[(l‐ethyl‐lH‐l,2,3‐triazol‐4‐yl)methoxy]‐4‐methyl‐2H‐chromen‐2‐ones ( 5a – l ). The structures of all the newly synthesized molecules were assigned by elemental analysis and spectral data. The synthesized compounds were screened for their antibacterial activities strains using Cup plate method.     

Phosphorescent Cyclometalated Iridium(III) Complexes That Contain Substituted 2‐Acetylbenzo[b]thiophen‐3‐olate Ligand for Red Organic Light‐Emitting Devices

We report the synthesis of a new class of thermally stable and strongly luminescent cyclometalated iridium(III) complexes 1 – 6 , which contain the 2‐acetylbenzo[b]thiophene‐3‐olate (bt) ligand, and their application in organic light‐emitting diodes (OLEDs). These heteroleptic iridium(III) complexes with bt as the ancillary ligand have a decomposition temperature that is 10–20 % higher and lower emission self‐quenching constants than those of their corresponding complexes with acetylacetonate (acac). The luminescent color of these iridium(III) complexes could be fine‐tuned from orange (e.g., 2‐phenyl‐6‐(trifluoromethyl)benzo[d]thiazole (cf₃bta) for 4 ) to pure red (e.g., lpt (Hlpt=4‐methyl‐2‐(thiophen‐2‐yl)quinolone) for 6 ) by varying the cyclometalating ligands (C‐deprotonated C^N). In particular, highly efficient OLEDs based on 6 as dopant (emitter) and 1,3‐bis(carbazol‐9‐yl)benzene (mCP) as host that exhibit stable red emission over a wide range of brightness with CIE chromaticity coordinates of (0.67, 0.33) well matched to the National Television System Committee (NTSC) standard have been fabricated along with an external quantum efficiency (EQE) and current efficiency of 9 % and 10 cd A^?1, respectively. A further 50 % increase in EQE (>13 %) by replacing mCP with bis[4‐(6H‐indolo[2,3‐b]quinoxalin‐6‐yl)phenyl]diphenylsilane (BIQS) as host for 6 in the red OLED is demonstrated. The performance of OLEDs fabricated with 6 (i.e., [(lpt)₂Ir(bt)]) was comparable to that of the analogous iridium(III) complex that bore acac (i.e., [(lpt)₂Ir(acac)]; 6 a in this work) [Adv. Mater.­ 2011 , 23, 2981] fabricated under similar conditions. By using ntt (Hnnt=3‐hydroxynaphtho[2,3‐b]thiophen‐2‐yl)(thiophen‐2‐yl)methanone) ligand, a substituted derivative of bt, the [(cf₃bta)₂Ir(ntt)] was prepared and found to display deep red emission at around 700 nm with a quantum yield of 12 % in mCP thin film.     

Convenient Synthesis of Substituted 5‐(Hydroxymethyl)‐8‐methyl‐3‐(4‐phenylquinazolin‐2‐yl)‐2H‐pyrano[2,3‐c]pyridin‐2‐ones

Abstract

Interaction of 2‐imino‐2H‐pyrano[2,3‐c]pyridin‐3‐carboxamide with substituted 2‐aminobenzophenones proceeds via recyclization mechanism leading to substituted 3‐(4‐arylquinazolyn‐2‐yl)‐2H‐pyrano[2,3‐c]pyridin‐2‐ones. Their reaction with acetic anhydride affords the O‐acylation products.     

Reversal of Regioselectivity of Nitrone Cycloadditions by Lewis Acids

The regio‐ and stereoselectivity of cycloadditions of the nitrone 1a and the chiral, sugar‐derived nitrones 13a and 13b with 3‐(prop‐2‐enoyl)‐1,3‐oxazolidin‐2‐one ( 2 ) depends on the nature of the Lewis acid catalyst used. Addition of Lewis acid reverses the regioselectivity of the cycloaddition, and improves the anti‐diastereoselectivity in the case of chiral nitrones. The sterically favored isoxazolidin‐5‐yl‐substituted adducts 3, 4 , and 14 – 17 are produced as the major products in the absence of Lewis acid, while the electronically favored regioisomers with isoxazolidin‐4‐yl substituents ( 5, 6 , and 18 – 21 , respectively) are obtained as major products in the [Ti(OⁱPr)₂Cl₂] catalyzed reactions. The reactions of nitrone 13b with 2 in the presence of other Lewis acids such as ZnCl₂, ZnBr₂, ZnI₂ and MgI₂/I₂ gave both regioisomeric pairs of the diastereoisomers, favoring the 4‐substituted congeners. The diastereoisomeric isoxazolidines 3a – 6a were reduced with NaBH₄ in THF/H₂O with subsequent desilylation to yield the separable diols 9 – 12 . Reduction of the diastereoisomeric isoxazolidines 19a and 18a afforded the chiral alcohols 23 and 22 , the latter of which was analyzed by X‐ray crystallography.     

Hydrothermal Preparation of a Series of Luminescent Cadmium(II) and Zinc(II) Coordination Complexes and Enhanced Real‐time Photo‐luminescent Sensing for Benzaldehyde

Two cadmium(II) and two zinc(II) coordination complexes with diverse structural motifs, [Cd₂(HL)I₃H₂O] · H₂O ( 1 ), [Cd₂(H₂L)₂(H₂O)₄] · 2SO₄ · 14H₂O ( 2 ), [Zn₃(L′)₂(H₂O)₆] · 4H₂O · 2(NO₃) ( 3 ), and [Zn₃L'₂(H₂O)₂Cl₂] · H₂O ( 4 ) [H₂L = 1,1‐bis(5‐(pyrid‐2‐yl)‐1,2,4‐triazol‐3‐yl)methane; H₂L′ = 1,1‐bis(5‐(pyrid‐2‐yl)‐1,2,4‐triazol‐3‐yl)methanone] were synthesized through a hydrothermal method. These coordination complexes were characterized by single‐crystal X‐ray diffraction, powder X‐ray diffraction (PXRD), FT‐IR spectroscopy, and photo‐luminescent experiments. Single crystal structural analysis revealed that 1 – 4 belong to polynuclear coordination compounds. PXRD analysis of 1 – 4 unambiguously confirmed the purity of the as‐synthesized coordination compounds. It is the first time to synthesize coordination compounds based on H₂L′, which reacted from the original material H₂L through in‐situ hydrothermal conditions. In addition, photo‐luminescent experiments revealed that 1 – 4 have real‐time sensing effects for benzaldehyde through fluorescence quenching. For 1 – 4 , the photo‐luminescent quenching effect for benzaldehyde was also compared and the coordination complexes 3 and 4 based on H₂L′ have higher photo‐luminescent quenching effect than compounds 1 and 2 .     

Nucleotides. Part LXXVI

A series of new fluorescing 8‐(6‐hydroxyhexyl)isoalloxazine (=8‐(6‐hydroxyhexyl)benzo[g]pteridine‐2,4(1H,3H)‐dione) derivatives 4 – 13 were synthesized from 6‐[(6‐hydroxyhexyl)amino]uracil ( 2 ) with 1‐chloro‐4‐nitrosobenzene via 8‐chloro‐10‐(6‐hydroxyhexyl)isoalloxazine ( 3 ) and subsequent substitution of the Cl‐atom of 3 by various amines (Scheme). Analogously, 8‐substituted 10‐{3‐[(2,2‐dimethyl‐1,3‐dioxolan‐4‐yl)methoxy]propyl}isoalloxazines 19, 20 , and 23 – 25 were prepared which yielded on deprotection the corresponding 10‐[3‐(2,3‐dihydroxypropoxy)propyl]alloxazines 21, 22 , and 26 – 28 . Their conversion into the 3″‐O‐(4,4′‐dimethoxytrityl) derivatives 29 – 33 and subsequent transformation into the corresponding 2″‐(2‐cyanoethyl N,N‐diisopropylphosphoramidites) 34 – 38 led to new building blocks for oligonucleotide synthesis. A series of 21‐mer oligodeoxyribonucleotides carrying the fluorescing isoalloxazine 37 in various positions of the chain were assembled in a DNA synthesizer. Combination with the complementary sequence yielded the stable duplexes 40 – 54 showing by the melting temperatures T_m that the fluorophor ( F ) does not harm the stability of the unmodified duplex 39 (Table).     

Synthesis, Structure and Biological Activities of Novel Triazole Compounds Containing 4,6-Dimethyl-pyrimidin-2-ylthio Group

Introduction As an important type of fungicides, triazole com-pounds are highly efficient, low poisonous and inward absorbent.1-3 At present, the studies on triazole deriva-tives are mainly concentrated on compounds with tria-zole as the only active group. The report on triazole compounds that contain both triazole group and other active group in a single molecule has rarely been found. Some pyrimidines have been used as highly efficient and lowly poisonous fungicides4 in controling powdery mi…     

Isocyanide‐Based Three‐Component Synthesis of Highly Substituted 1,6‐Dihydro‐6,6‐dimethylpyrazine‐2,3‐dicarbonitrile, 3,4‐Dihydrobenzo[g]quinoxalin‐2‐amine,and 3,4‐Dihydro‐3,3‐dimethyl‐quinoxalin‐2‐amine Derivatives

A novel and efficient isocyanide‐based multicomponent reaction between alkyl or aryl isocyanides 1 , 2,3‐diaminomaleonitrile ( 2 ), naphthalene‐2,3‐diamines ( 6 ) or benzene‐1,2‐diamine ( 9 ), and 3‐oxopentanedioic acid ( 3 ) or Meldrum's acid ( 4 ) or ketones 7 was developed for the ecologic synthesis, at room temperature under mild conditions, of 1,6‐dihydropyrazine‐2,3‐dicarbonitriles 5a – 5f in H₂O without using any catalyst, and of 3,4‐dihydrobenzo[g]quinoxalin‐2‐amine and 3,4‐dihydro‐3,3‐dimethyl‐quinoxalin‐2‐amine derivatives 8a – 8g and 10a – 10e , respectively, in the presence of a catalytic amount of p‐toluenesulfonic acid (TsOH) in EtOH, in good to excellent yields (Scheme 1).     

Copper(II)‐ and gold(III)‐mediated cyclization of a thiourea to a substituted 2‐aminobenzothiazole

Benzothiazole derivatives are a class of privileged molecules due to their biological activity and pharmaceutical applications. One route to these molecules is via intramolecular cyclization of thioureas to form substituted 2‐aminobenzothiazoles, but this often requires harsh conditions or employs expensive metal catalysts. Herein, the copper(II)‐ and gold(III)‐mediated cyclizations of thioureas to substituted 2‐aminobenzothiazoles are reported. The single‐crystal X‐ray structures of the thiourea N‐(3‐methoxyphenyl)‐N ′‐(pyridin‐2‐yl)thiourea, C₁₃H₁₃N₃OS, and the intermediate metal complexes aquabis[5‐methoxy‐N‐(pyridin‐2‐yl‐κN )‐1,3‐benzothiazol‐2‐amine‐κN ³]copper(II) dinitrate, [Cu(C₁₃H₁₁N₃OS)₂(H₂O)](NO₃)₂, and bis{2‐[(5‐methoxy‐1,3‐benzothiazol‐2‐yl)amino]pyridin‐1‐ium} dichloridogold(I) chloride monohydrate, (C₁₃H₁₂N₃OS)₂[AuCl₂]Cl·H₂O, are reported. The copper complex exhibits a distorted trigonal–bipyramidal geometry, with direct metal‐to‐benzothiazole‐ligand coordination, while the gold complex is a salt containing the protonated uncoordinated benzothiazole, and offers evidence that metal reduction (in this case, Au^III to Au^I) is required for the cyclization to proceed. As such, this study provides further mechanistic insight into the role of the metal cations in these transformations.     

Microwave‐Assisted Synthesis of Novel Spiro Phosphonyl Thiazolo Pyrazole Glycosides as Potential Nematicidal Agents

A series of novel dimethyl 7‐((3aR,5S,6S,6aR)‐6‐((1‐(4‐chlorophenyl)‐1H‐1,2,3‐triazol‐4‐yl)methoxy)‐2,2‐dimethyltetrahydrofuro[2,3‐d][1,3]dioxol‐5‐yl)‐4‐(4‐fluorophenyl)‐9‐oxo‐8‐phenyl‐6‐thia‐1,2,8‐triazaspiro[4.4]non‐2‐en‐3‐ylphosphonate 2a – g were synthesized by the reaction of chalcone derivatives of 2‐((3aR,5S,6S,6aR)‐6‐((1‐(4‐chlorophenyl)‐1H‐1,2,3‐triazol‐4‐yl)methoxy)‐2,2‐dimethyltetrahydrofuro[2,3‐d][1,3]dioxol‐5‐yl)‐3‐phenylthiazolidin‐4‐one 1 with Bestmann–Ohira reagent. The chemical structures of newly synthesized compounds were elucidated by IR, NMR, MS, and elemental analysis. The compounds 2a – g were evaluated for their nematicidal activity against Dietylenchus myceliophagus and Caenorhabditis elegans; compounds 2b , 2c , 2g , and 2f showed appreciable nematicidal activity.