Synthesis and antimicrobialactivity of 2‐alkylcarbamato‐2,3‐dihydro‐5‐propylthio‐1H‐1,3,2‐benzodiazaphosphole 2‐oxides

Novel 2‐alkylcarbamato/thiocarbama‐to‐2,3‐dihydro‐5‐propylthio‐1H‐1,3,2‐benzodiazaphos‐phole 2‐oxides ( 4a–J ) were synthesized by cyclization of 4‐propylthio‐1,2‐phenylenediamine ( 3 ) with the corresponding dichlorophosphoryl carbamates/thiocarbamates ( 2a–J ) that were obtained by the addition of alcohols/thiols to isocyanatophosphoryl dichloride ( 1 ). The structures of the title compounds were confirmed by the ¹H, ¹³C, ³¹P NMR, and mass spectral studies. Some of these products were found to possess significant antimicrobial activity. © 2000 John Wiley & Sons, Inc. Heteroatom Chem 11:336–340, 2000     

Synthesis and antimicrobial activity of 2‐substituted‐2,3‐dihydro‐5‐propoxy‐1H‐1,3,2‐benzodiazaphosphole 2‐Oxides

Several 2‐alkylcarbamato/thiocarbamato/aryloxy/trichloromethyl‐2,3‐dihydro‐5‐propoxy‐1H‐1,3,2‐benzodiazaphosphole 2‐oxides ( 4 and 6 ) were synthesised by reacting 4‐propoxy‐o‐phenylenediamine ( 1 ) with various N‐dichlorophosphinyl carbamates ( 3 ), aryl phosphorodichloridates ( 5a‐f ) and trichloromethyl phosphonic dichloride ( 5g ) in the presence of triethylamine at 45‐65 °C. Their ir, ¹H, ¹³C, ³¹P nmr and mass spectral data are discussed. The compounds were screened for antifungal activity against Curvularia lunata and Aspergillus niger and for antibacterial activity against Bacillus subtilis and Escherichia coli. Most of these compounds exhibited moderate activity in the assays.     

Synthesis of 2‐substituted‐2,3‐dihydro‐5‐benzoyl‐1H‐1,3,2‐benzodiazaphosphole 2‐oxides/sulfides

Syntheses of 2‐aryloxy/2‐chloro ethoxy‐2,3‐dihydro‐5‐benzoyl‐1H‐1,3,2‐benzodiaza‐phosphole 2‐oxides 3a–h were accomplished by reactions of equimolar quantities of 3,4‐diaminobenzophenone ( 1 ) with various aryl/chloroethoxy phosphorodichloridates 2a–g and 2h in the presence of triethylamine at 50–60°C. Compounds 3i–k were prepared by reacting 3,4‐diaminobenzophenone ( 1 ) with aryl thiophosphorodichloridates 2i–k under similar conditions. They were characterized by IR, ¹H, ¹³C, and ³¹P NMR spectral data. Some of these products possessed siginificant antimicrobial activity © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:340–345, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10044     

Synthesis and antimicrobial activity of 2,10‐dichloro‐6‐substituted‐4,8‐dinitro‐12H‐dibenzo[d,g][1,3,2]dioxaphosphocin 6‐oxides/sulfides

Novel 2,10‐dichloro‐6‐substituted‐4,8‐dinitro‐12H‐dibenzo[d,g][1,3,2]dioxaphosphocin 6‐oxides ( 4a–h ) were synthesized by reacting 5,5′‐dichloro‐3,3′‐dinitro‐2,2′‐dihydroxydiphenylmethane ( 2 ) with different aryl phosphorodichloridates ( 3a–g ) or bis(2‐chloroethyl)phosphoramidic dichloride ( 3h ) in the presence of triethylamine at 55–60°C, and the compounds 4i–l were prepared by reacting the 2,6,10‐trichloro‐4,8‐dinitro‐12H‐dibenzo[d,g][1,3,2]dioxaphosphocin 6‐sulfide ( 5 ) in situ with substituted phenols and thiophenol 5 was prepared by condensing 2 with thiophosphoryl chloride. IR, ¹H, ¹³C, ³¹P NMR, and mass spectra supported all the proposed structures. Several title compounds exhibited significant activity in the assays against the bacteria Bacillus subtilis and Escherichia coli and fungi Curvularia lunata and Aspergillus niger. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:10–15, 2001     

Synthesis and antimicrobial activity of 8‐alkylcarbamato‐16H‐dinaphtho [2,1‐d:1′,2′‐g] 1,3,2‐dioxaphosphocin 8‐oxides

A new family of phosphorus heterocycles, namely 8‐alkylcarbamato‐16H‐dinaphtho‐[2,1‐d: 1′,2′‐g] 1,3,2‐dioxaphosphocin 8‐oxides ( 4a–j ) has been obtained by reaction of bis(2‐hydroxy‐1‐naphthyl)methane ( 3 ) with a series of dichlorophosphosphinyl carbamates ( 2a–j ) in dry toluene in the presence of triethylamine at 40–45°C. The intermediates 2a–j were obtained by the addition of alcohols/thiol to isocyanatophosphonic dichloride ( 1 ) at −10°C in dry toluene. The structures of the title compounds were confirmed by the elemental analyses, IR, ¹H, ¹³C, and ³¹P NMR spectra. The FAB mass spectrum of one member of the family is discussed. These compounds were found to possess good antimicrobial activity. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:16–20, 2001     

Synthesis of alkyl 6‐methyl‐4‐(2‐pyridyl)‐1,2,3,4‐tetrahydro‐2H‐pyrimidine‐2‐one‐5‐carboxylates for evaluation as calcium channel antagonists

The Bigenelli acid catalyzed condensation of 2‐pyridylcarboxaldehyde ( 1 ), urea ( 2 ) and an alkyl acetoacetate ( 3 ) afforded the respective alkyl (Me, Et, i‐Pr, i‐Bu, t‐Bu) 6‐methyl‐4‐(2‐pyridyl)‐1,2,3,4‐tetrahydro‐2H‐pyrimidine‐2‐one‐5‐carboxylates ( 4a‐e ). The most potent calcium channel antagonist ethyl 6‐methyl‐4‐(2‐pyridyl)‐1,2,3,4‐tetrahydro‐2H‐pyrimidine‐2‐one‐5‐carboxylate ( 4b , IC₅₀ = 1.67 × 10^?5 M) wasa much weaker calcium channel antagonist than the reference drug nifedipine (Adalat®, IC₅₀ = 1.40 × 10^?8 M) on guinea pig ileal longitudinal smooth muscle (GPILSM). The alkyl 6‐methyl‐4‐(2‐pyridyl)‐1,2,3,4‐tetrahydro‐2H‐pyrimidine‐2‐one‐5‐carboxylates did not show any inotropic effect on heart since no increase, or decrease, in the contractile force of guinea pig left atrium was observed. These structure activity studies show that the alkyl 6‐methyl‐4‐(2‐pyridyl)‐1,2,3,4‐tetrahydro‐2H‐pyrimidine‐2‐one‐5‐carboxylates ( 4a‐e ) are partial bioisosteres of nifedipine with respect to calcium channel antagonist activity on guinea pig ileal longitudinal smooth muscle (GPILSM).     

Microsynthesis and mass spectral study of Chemical Weapons Convention related 2‐alkyl‐1,3,6,2‐dioxathiaphosphocane‐2‐oxides

Chemical Weapons Convention (CWC)‐related compounds where the phosphorus atom is part of a ring have very limited representation in mass spectral libraries and the open literature. Here we report electron ionization (EI), chemical ionization (CI) and electrospray ionization tandem mass spectrometry (ESI‐MSⁿ) spectra and retention indices for 2‐alkyl‐1,3,6,2‐dioxathiaphosphocane‐2‐oxides (alkyl C₁ to C₃) which are new cyclic chemicals covered under the CWC. The EI mass spectra show a pattern of ion fragmentation that is similar to that of other cyclic phosphonates in that loss of the alkylphosphonic acid as a neutral loss is more important than the presence of the protonated alkylphosphonic acid. In contrast to other cyclic phosphonates, the 2‐alkyl‐1,3,6,2‐dioxathiaphosphocane‐2‐oxides show almost no protonated alkylphosphonic acid and as a result the spectra do not carry the same distinctive signature of the phosphorus–carbon bond that is required for the chemical to be covered under the CWC. Copyright © 2008 John Wiley & Sons, Ltd.     

Synthesis,spectral characterization,and biological evaluation of imidazole‐substituted pyridine‐2‐amine and benzo‐substituted imidazole‐2‐amine

A series of new imidazole‐substituted pyridine‐2‐amine and benzo‐substituted imidazol‐2‐amine 3 – 12 were synthesized by treating various amines 1(a – d) with alkyl/aryl isothiocyanate 2(a‐c) at 60–90°C in isopropyl alcohol without using any catalyst with high yields. The structures of all the newly synthesized compounds were characterized using IR, NMR (¹H, ¹³C), mass, and elemental analyses. All the newly synthesized compounds were screened for their in vitro antioxidant and antimicrobial activities to understand their biological potency. All the title compounds exhibited good antioxidant and antimicrobial activities in vitro when compared to the standard drugs.     

Facile syntheses and antimicrobial studies of 6‐(aryloxy/arylthio/chloroethoxy)‐2,10‐dichloro‐4,8‐dinitro‐12‐trichloromemyl‐12H‐dibenzo[d,g][13,2]dioxaphosphocin 6‐oxides

Synthesis of several novel 6‐aryloxy/arylmio/chloroethoxy‐2,10‐dichloro‐4,8‐dinitro‐12‐trichloro‐memyl‐12H‐dibenzo[d,g][1,3,2]dioxaphosphocin 6‐oxides ( 4a‐k ) was accomplished by reacting 2,2‐bis (2‐hydroxy‐5‐chloro‐3‐nitrophenyl)‐1,1,1‐trichloroethane 2 with different aryl phosphorodichloridates ( 3a‐g ) and O‐2‐chloroethyl phosphoryldichloride ( 3h ) in the presence of triethylamine in dry toluene at 60–65 °C. Actually some of these compounds were prepared by reacting monochloride 5 resulting from the condensation of phosphorus oxychloride with 2 in situ, with different phenols and thiophenols. The chemical structures were confirmed by elemental, ir and ¹H, ¹³C, ³¹P nmr and mass spectral data analyses. These compounds were screened for antifungal activity against Aspergillus flavus, Alternaria alternata, Fusarium solani, Curvularia lunata and Pyricularia oryzae and antibacterial activity on Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas syringae and Klebsiella pneumoniae. Some of them possessed significant activity.     

Synthesis and antimicrobial activity of novel 3 substituted 1,5‐dihydro‐2,4,3‐benzodioxaphosphepine 3‐oxides

Novel 3 substituted 1,5‐dihydro‐2,4,3‐benzodioxaphosphepine 3‐oxides ( 5a–h ) were synthesized by reacting 1,2‐benzenedimethanol ( 1 ) with phosphorus tribromide in the presence of triethylamine at 0–30°C and subsequent reaction of the monobromide ( 2 ) with different Grignard reagents ( 3 ) at room temperature. The products ( 4 ) were converted to corresponding oxides 5a–i by oxidation with H₂O₂ at room temperature. The chemical structures of all the products were confirmed by analytical, IR and NMR (¹H, ¹³C, and ³¹P) spectral data. Their antifungal and antibacterial activity is also evaluated. Most of these compounds exhibited moderate antimicrobial activity in the assay. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:572–575, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20154     

Synthesis of alkyl 6‐methyl‐4‐(2‐trifluoromethylphenyl)‐1,2,3,4‐tetrahydro‐2H‐pyrimidine‐2‐one‐5‐carboxylates possessing a N‐3 nitro substituent to determine calcium channel modulation structure‐activity relationships

The Bigenelli acid catalyzed condensation of 2‐trifluoromethylbenzaldehyde ( 1 ), urea ( 2 ) and an alkyl acetoacetate ( 3 ) afforded the respective alkyl (Me, Et, i‐Pr, i‐Bu) 6‐methyl‐4‐(2‐trifluoromethylphenyl)‐1,2,3,4‐tetrahydro‐2H‐pyrimidine‐2‐one‐5‐carboxylate ( 4‐7 ). Subsequent N³‐nitration of the alkyl esters ( 4‐7 ) using Cu(NO₃)₂ 3H₂O and Ac₂O furnished the target alkyl 6‐methyl‐3‐nitro‐4‐(2‐trifluoromethylphenyl)‐1,2,3,4‐tetrahydro‐2H‐pyrimidine‐2‐one‐5‐carboxylates ( 8‐11 ). The N³‐nitro compounds ( 8‐11 ) were less potent calcium channel antagonists (IC₅₀ values in the 1.9 × 10^?7 to 3.9 × 10^?6 M range) on guinea pig ileal longitudinal smooth muscle than the reference drug nifedipine (Adalat®, IC₅₀ = 1.4 × 10^?8 M). In vitro calcium channel modulation studies on guinea pig left atrium (GPLA) showed that the methyl and ethyl esters ( 8‐9 ) induced a weak‐to‐modest positive inotropic (agonist) effect, and that the inactive isopropyl ( 10 ) and isobutyl ( 11 ) esters did not alter the cardiac contractile force of GPLA.     

Synthesis and antimicrobial activity of novel 2‐alkyl/arylcarbamato‐6‐(1,1‐dimethylethyl)‐3‐cyclohexyl‐3,4‐dihydro‐2H‐1,3,2‐benzoxazaphosphorine‐2‐oxides

Novel 2‐alkyl/arylcarbamato‐6‐(1,1‐dimethylethyl)‐3‐cyclohexyl‐3,4‐dihydro‐2H‐1,3,2‐benzoxaza‐phosphorine‐2‐oxides ( IV ) have been synthesized from reactions of 2‐cyclohexylaminomethyl‐4‐t‐butylphenol I [8c] with various dichlorophosphinyl carbamates ( III ) [8a‐b] in dry toluene in the presence of triethylamine at 40‐50 °C. All the title compounds ( IVa‐j ) at reflux temperature are degraded to 2‐amino‐6‐(1,1‐dimethylethyl)‐3‐cyclohexyl‐3,4‐dihydro‐2H‐1,3,2‐benzoxazaphosphorine‐2‐oxide ( IVk ) exclusively. The structures are determined by ir, nmr and mass spectral studies. They were screened for antifungal activity against Penicillium notatum, Aspergillus niger and Helminthosporium sps, and antibacterial activity on Escherchia coli, Staphylococcus aureus and Pseudomonas aeruginosa. A few of them possess significant activity.     

Efficient Synthesis of Novel 3‐Phenyl‐5‐thioxo‐3,4,5,6‐tetrahydroimidazo[4,5‐c]pyrazole‐2(1H)‐carbothioamide Derivatives Using a CeO2–MgO Catalyst and Evaluation of Antimicrobial Activity

Imidazo[4,5‐c ]pyrazole derivatives ( 3a–f , 4a–f , and 5a–f ) were efficiently synthesized by one‐pot three‐component reactions using CeO₂–MgO as the catalyst. The synthesized compounds were characterized by IR, ¹H NMR, ¹³C NMR, and mass spectroscopic analyses. The in vitro antimicrobial activity of the synthesized compounds against various bacterial and fungal strains was screened. Compound 3b was highly active [minimum inhibitory concentration (MIC): 0.5 μg/mL] against Gram‐positive Staphylococcus aureus , and compounds 3b , 3f , 4d , and 4e were highly active (MIC: 0.5, 2, 2, and 0.5 μg/mL, respectively) against Gram‐negative Pseudomonas aeruginosa and Klebsiella pneumoniae , relative to standard ciprofloxacin in the antibacterial activity screening. Compounds 3b and 4f were highly active (MIC: 4 and 0.5 μg/mL, respectively) against Aspergillus fumigatus and Microsporum audouinii in the antifungal activity screening compared with the clotrimazole standard.     

A facile synthesis and antimicrobial activity of 2,10‐dichloro‐6‐(aryloxy/thiophenoxy)‐4,8‐dinitrodibenzol[d,g][1,3,6,2]‐dioxathiaphosphocin‐ 6‐oxides

Novel 6‐substituted 2,10‐dichloro‐4,8‐dinitrodibenzo[d,g][1,3,6,2]dioxathiaphosphocin‐6‐oxides 4 were synthesized by reacting 5,5′‐dichloro‐3,3′‐dinitro‐2,2′‐dihydroxydiphenyl sulfide ( 2 ) with different aryl phosphorodichloridates, trichloromethylphosphonic dichloride and O‐2‐chloroethyl phosphoryldichloride (3) in the presence of triethylamine at 55–60°. Some of these compounds are prepared by reacting the monochloride, 2,6,10‐trichloro‐4,8‐dinitrodibenzo[d,g][1,3,6,2]dioxathiaphosphoein‐6‐oxide ( 5 ) in situ with substituted phenols and thiols. 5 is prepared by condensing 2 with phosphorus oxychloride. The ¹H nmr chemical shifts of the dibenzodioxathiaphosphocin moiety indicates the presence of more than one conformer in solution. However the presence of more than one conformer in each example cannot be entirely eliminated. Interestingly 4d on oxidation to 12‐sulphone by H₂O₂ in acetic acid medium yielded only 12‐sulphoxide 6a . The ir, ¹H, ¹³C, ³¹P nmr and mass spectral data are discussed. Some of these compounds were screened for antifungal activity against Curvularia lunata and Aspergillus niger and antibacterial activity on Bacillus subtilis and Klebsiella pneumoniae. A few of them possess significant activity.     

Study of synthesis of 2‐(2‐alkoxyphenyl)‐1H‐imidazoles. Comparison of oxidative aromatization reactions of imidazolines

The reaction of methyl salicylate with ethane‐1,2‐diamine has been used to prepare 2‐(2‐hydroxyphenyl)‐1H‐imidazoline. This compound was alkylated with alkyl halides to give five new 2‐(2‐alkoxyphenyl)‐1H‐imidazolines (alkyl = propyl, isopropyl, isobutyl, sec‐butyl, benzyl). Seven types of transformation reactions of imidazolines into the respective imidazoles were tested. Out of them successful were the dehydrogenation on palladium in toluene (several‐day refluxing), oxidation with activated manganese dioxide in toluene (several‐hour heating at 60 °C), and the oxidation with potassium nitrosodisulfonate (Fremy's salt) at room temperature. Seven new 2‐(2‐alkoxyphenyl)‐1H‐imidazoles were synthesized (alkyl = ethyl, propyl, isopropyl, butyl, isobutyl, sec‐butyl, benzyl) via mentioned methods. Comparison of individual oxidative aromatization reactions is discussed from the point of view of experimental arrangement, reaction time and conditions, purity of the products obtained, and yields.     

Synthesis of New Gluco‐, Galacto‐, and Mannopyranosylthiazoles,Thiazolidinones, and Pyranosylthiazlidin‐4‐ones from Sugar Thiosemicarbazone Derivatives

A new series of potentially biological active derivatives, namely alkyl‐2‐((4‐oxo‐2‐(phenylimino)‐3‐(β‐d ‐pyranosyl‐2‐ylamino)thiazolidine‐5‐ylidene)acetate ( 5a–f ), 4‐(4‐bromophenyl)thiazol‐2(3H)‐ylidene)hydrazinyl)‐β‐d ‐pyranosyl ( 4a–c ), and 5‐(4‐bromophenyl)‐2‐(phenylimino)‐3‐(β‐d ‐pyranosyl‐2‐ylamino)thiazolidine‐4‐one ( 6 ) were synthesized via a reaction of the sugar thiosemicarbazone derivatives with 2,4′‐dibromoacetophenone, dialkylacetylenedicarboxylate, and ethylbromoacetate, respectively. The structures of the synthesized compounds were established by spectroscopic methods (FT‐IR, ¹H NMR, ¹³C NMR, and 2D NMR) and elemental analyses. Furthermore, the effect of various solvents at reflux and also ambient temperature on the reactions of the sugar thiosemicarbazone with 2,4′dibromoacetophenone, diethyl acetylenedicarboxylate, and dimethyl acetylenedicarboxylate was investigated. © 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:200–207, 2013; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21083     

Synthesis of 2‐(sulfamoylphenyl)‐4′‐(iminoaryl/hetroaryl)‐4‐(4′′‐hydroxyphenyl)‐thiazoles and their O‐glucosides

In continuation of our work, we synthesized 2‐(sulfamoylphenyl)‐4′‐amino‐4‐(4″‐hydroxyphenyl)‐thiazole ( 3a ), which were reacted with various (aryl/hetroaryl) aldehyde to form 2‐(sulfamoylphenyl)‐4′‐(iminoaryl/hetroaryl)‐4‐(4″‐hydroxyphenyl)‐thiazoles ( 4a , 4b , 4c , 4d , 4e , 4f ). Glucosylation of compounds ( 4a , 4b , 4c , 4d , 4e , 4f ) have been done by using acetobromoglucose as a glucosyl donor to afford 2‐(sulfamoylphenyl)‐4′‐(iminoaryl/hetroaryl)‐4‐(2,3,4,6‐tetra‐O‐acetyl‐4″‐O‐β‐D ‐glucosidoxyphenyl)‐thiazoles ( 5a , 5b , 5c , 5d , 5e , 5f ), further on deacetylation to produce 2‐(sulfamoylphenyl)‐4′‐(iminoaryl/hetroaryl)‐4‐(4″‐O‐β‐D ‐glucosidoxyphenyl)‐thiazoles ( 6a , 6b , 6c , 6d , 6e , 6f ). The compounds are confirmed by FTIR, ¹H‐NMR, ¹³C‐NMR, and ES‐Mass spectral analysis. J. Heterocyclic Chem., (2011).     

Synthesis and antioxidant activities of novel N‐aryl (and N‐alkyl) γ‐ and δ‐imino esters and ketimines

Novel N‐aryl (and N‐alkyl) γ‐ and δ‐imino esters 2a–g ( 3a–g ) and N‐aryl (and N‐alkyl) ketimines 2h–j ( 3h–j ) were synthesized in high yields (80–99%) from their corresponding γ‐ and δ‐keto esters and ketones in this study. The structures of the synthesized compounds were clarified by Fourier transform infrared (FT‐IR), NMR (¹H and ¹³C), mass spectrometry, and elemental analyses. Isomerizations [E/Z] were also determined by their ¹H NMR spectra. The free‐radical scavenging activity of imines was evaluated using the 1,1‐diphenyl‐2‐picryl‐hydrazyl (DPPH) method. The relationships between the structure and antioxidant activity of these compounds are discussed. Among these compounds, 2a–c (at the concentration 1000 μg/mL) exhibit high antioxidant activity similar to those of the standards (butylated hydroxyanisole [ BHA], butylated hydroxytoluene [ BHT], and ascorbic acid).     

Synthesis of New (Pyrazol‐3‐yl)‐1,3,4‐oxadiazole Derivatives by Unexpected Aromatization During Oxidative Cyclization of 4,5‐Dihydro‐1H‐pyrazole‐3‐carbohydrazones and Their Biological Activities

A series of novel 2‐(4‐(4‐chlorophenyl)‐1H‐pyrazol‐3‐yl)‐5‐(Aryl)‐1,3,4‐oxadiazoles were synthesized by unexpected aromatization during oxidative cyclization of 4‐(4‐chlorophenyl)‐4,5‐dihydro‐1H‐pyrazole‐3‐carbohydrazones using chloramine‐T as an oxidant. The hydrazones were derived from 4‐(4‐chlorophenyl)‐4,5‐dihydro‐1H‐pyrazole‐3‐carbohydrazide and various substituted aldehydes. The structure of the synthesized compounds was confirmed by FTIR, ¹H NMR, ¹³C NMR, and mass spectral data. The synthesized compounds were evaluated for their antitubercular and antioxidant activities. All the compounds 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h and 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h showed good antitubercular activity against Mycobacterium tuberculosis (minimum inhibitory concentration = 25 µg/mL for 4f and 4g , 50–100 µg/mL for the rest). However, all the compounds exhibited poor antioxidant activity against 1,1‐diphenyl‐2‐picryl‐hydrazil free radical.     

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.