ABSTRACT
The reactivity of α-azidochalcones has been explored for the preparation of highly substituted oxazoles via a 2H-azirine intermediate. The azidochalcones, when treated with potassium thiocyanate in the presence of potassium persulfate, lead to 2,4,5-trisubstituted oxazoles in good yields. Incidentally, 2-aminothiazoles are the products when ferric nitrate is employed instead of persulfate in the above reaction.
ABSTRACT
An efficient synthesis of dihydro-4H-benzo[4,5]imidazo[2,1-b]pyrano[2,3-d]thiazole by a multicomponent route starting from 2-((1H-benzo[d]imidazol-2-yl)thio)-1-phenylethan-1-one, an aromatic aldehyde and malononitrile is described. This protocol features a metal free approach with good substrate scope and decent yield. The heterocyclic skeleton obtained in this study may have interesting biological properties.
ABSTRACT
A simple, efficient and green procedure for the synthesis of novel 2,4-diaryl-5,6-dihydrobenzo[j][1,7]phenanthrolines has been developed via a Krohnke-type one-pot three-component reaction of 2-[arylmethylidene]-3,4-dihydro-1(2H)-acridinones and (2-aryl-2-oxoethyl)pyridinium bromides in the presence of excess ammonium acetate in good yields under solvent-free conditions. Good functional group tolerance, high substrate scope and no column purification are the practical advantages of this methodology.
Subject(s)
Phenanthrolines/chemical synthesis , Chemistry Techniques, SyntheticABSTRACT
Expedient synthesis of benzosuberone-tethered spirooxindoles was accomplished by a three-component 1,3-dipolar cycloaddition reaction between azomethine ylide (generated in situ) and arylidene benzosuberone. This protocol offers good yield and wide functional group tolerance under mild reaction condition with high regio- and stereoselectivities.
Subject(s)
Azo Compounds/chemistry , Coumarins/chemistry , Oxindoles/chemistry , Oxindoles/chemical synthesis , Spiro Compounds/chemistry , Thiosemicarbazones/chemistry , Cycloaddition Reaction , StereoisomerismABSTRACT
Herein, the fluorescent carbon dots (CDs) with blue emission were prepared by hydrothermal treatment using pineapple peel as a source of carbon. The as-prepared CDs exhibited turn-Off fluorescence behavior toward Hg2+ and subsequent turn-On behavior for l-cysteine along with enhanced biocompatibility and negligible cytotoxicity for cell imaging. The practical applicability of carbon dots was used for the quantification of Hg2+ in water. On the basis of the spectral characteristic changes, we have designed individual elementary logic operations such as NOT and IMP gates, by utilizing CD as probe and Hg2+ and l-Cys as chemical inputs. We have also demonstrated the utility of this system in electronic security devices and as memory element, with the idea of the switching.
ABSTRACT
An efficient one-pot microwave assisted stereoselective synthesis of novel dihydro-2'H-spiro[indene-2,1'-pyrrolo[3,4-c]pyrrole]-tetraone derivatives through three-component 1,3-dipolar cycloaddition of azomethine ylides generated in situ from ninhydrin and sarcosine with a series of 1-aryl-1H-pyrrole-2,5-diones is described. The synthesised compounds were screened for their antimycobacterial and AChE inhibition activities. Compound 4b (IC50 1.30µM) has been found to display twelve fold antimycobacterial activity compared to cycloserine and it is thirty seven times more active than pyrimethamine. Compound 4h displays maximum AchE inhibitory activity with IC50 value of 0.78±0.01µmol/L.
Subject(s)
Acetylcholinesterase/metabolism , Antitubercular Agents/chemical synthesis , Microwaves , Pyrroles/chemistry , Acetylcholinesterase/chemistry , Antitubercular Agents/chemistry , Antitubercular Agents/pharmacology , Cholinesterase Inhibitors/chemical synthesis , Cholinesterase Inhibitors/chemistry , Cholinesterase Inhibitors/pharmacology , Crystallography, X-Ray , Drug Design , Enzyme Activation/drug effects , Inhibitory Concentration 50 , Microbial Sensitivity Tests , Molecular Conformation , Mycobacterium tuberculosis/drug effects , Pyrroles/chemical synthesis , Pyrroles/pharmacology , Stereoisomerism , Structure-Activity RelationshipABSTRACT
A facile stereoselective synthesis of novel dispiro indeno pyrrolidine/pyrrolothiazole-thiochroman hybrids has been achieved by 1,3-dipolar cycloaddition of azomethine ylides, generated in situ from ninhydrin and sarcosine/thiaproline, on a series of 3-benzylidenethiochroman-4-ones. The synthesised compounds were screened for their antimycobacterial, anticancer and AchE inhibition activities. Compound 4l (IC50 1.07µM) has been found to exhibit the most potent antimycobacterial activity compared to cycloserine (12 times), pyrimethamine (37 times) and ethambutol (IC50 <1.56µM) and 6l (IC50=2.87µM) is more active than both cycloserine (4 times) and pyrimethamine (12 times). Three compounds, 4a, 6b and 6i, display good anticancer activity against CCRF-CEM cell lines. Compounds 6g and 4g display maximum AchE inhibitory activity with IC50 values of 1.10 and 1.16µmol/L respectively.
Subject(s)
Acetylcholinesterase/metabolism , Anti-Bacterial Agents/pharmacology , Antineoplastic Agents/pharmacology , Cholinesterase Inhibitors/pharmacology , Mycobacterium tuberculosis/drug effects , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/chemistry , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Cholinesterase Inhibitors/chemical synthesis , Cholinesterase Inhibitors/chemistry , Chromones/chemistry , Chromones/pharmacology , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Humans , Indenes/chemistry , Indenes/pharmacology , Microbial Sensitivity Tests , Models, Molecular , Molecular Structure , Pyrrolidines/chemistry , Pyrrolidines/pharmacology , Spiro Compounds/chemistry , Spiro Compounds/pharmacology , Stereoisomerism , Structure-Activity Relationship , Thiazoles/chemistry , Thiazoles/pharmacologyABSTRACT
An efficient synthesis of 3-substituted-5-arylamino-1,2,4-thiadiazoles through intramolecular oxidative S-N bond formation of imidoyl thioureas by phenyliodine(III) bis(trifluoroacetate) is reported. The protocol features a metal-free approach, broad substrate scope, very short reaction times, good to excellent yields, and simple starting materials.
ABSTRACT
A novel protocol for the synthesis of 3-nitro-N-aryl/alkylthiophen-2-amines in good yields from the reaction of α-nitroketene N,S-aryl/alkylaminoacetals and 1,4-dithiane-2,5-diol in the presence of K2CO3 in refluxing ethanol is described. This transformation generates two C-C bonds in a single operation and presumably proceeds through a reaction sequence comprising 2-mercaptoacetaldehyde generation, nucleophilic carbonyl addition, annelation and elimination steps.
ABSTRACT
The reaction of α-azidochalcones with carboxylic acids has been investigated resulting in the formation of α-amido-1,3-diketones under microwave irradiation via in situ formation of 2H-azirine intermediates. An interesting reaction is described wherein, with trifluoroacetic acid at lower temperature, it affords highly substituted 2-(trifluoromethyl)oxazoles. These flexible transformations proceed under solvent free conditions in good to excellent yields without any catalyst.
ABSTRACT
The synthesis of highly substituted imidazole derivatives has been achieved from various α-azido chalcones, aryl aldehydes, and anilines. This multicomponent protocol employs erbium triflate as a catalyst resulting in excellent yield of the imidazoles.
Subject(s)
Aldehydes/chemistry , Aniline Compounds/chemistry , Chalcones/chemistry , Erbium/chemistry , Imidazoles/chemical synthesis , Mesylates/chemistry , Catalysis , Imidazoles/chemistry , Molecular StructureABSTRACT
Pseudomonas aeruginosa PGPR2 was found to protect mungbean plants from charcoal rot disease caused by Macrophomina phaseolina. Secondary metabolites from the culture supernatant of P. aeruginosa PGPR2 were extracted with ethyl acetate and the antifungal compound was purified by preparative HPLC using reverse phase chromatography. The purified compound showed antifungal activity against M. phaseolina and other phytopathogenic fungi (Fusarium sp., Rhizoctonia sp. Alternaria sp., and Aspergillus sp.). The structure of the purified compound was determined using (1)H, (13)C, 2D NMR spectra and liquid chromatography-mass spectrometry (LC-MS). Spectral data suggest that the antifungal compound is 3,4-dihydroxy-N-methyl-4-(4-oxochroman-2-yl)butanamide, with the chemical formula C14H17NO5 and a molecular mass of 279. Though chemically synthesized chromanone derivatives have been shown to have antifungal activity, we report for the first time, the microbial production of a chromanone derivative with antifungal activity. This ability of P. aeruginosa PGPR2 makes it a suitable strain for biocontrol.
Subject(s)
Antibiosis , Antifungal Agents/chemistry , Plant Diseases/microbiology , Pseudomonas aeruginosa/chemistry , Antifungal Agents/isolation & purification , Ascomycota/drug effects , Ascomycota/pathogenicity , Molecular StructureABSTRACT
A novel strategy of copper(I)-catalyzed cascade intramolecular nucleophilic attack on N-sulfonylketenimine followed by rearrangement of sulfonimidates to sulfonamides resulting in a library of substituted 8,9-dihydro-5H-imidazo[1,2-a][1,4]diazepin-7(6H)-ones has been developed.
Subject(s)
Azepines/chemistry , Copper/chemistry , Imidazoles/chemistry , Sulfonamides/chemical synthesis , Catalysis , Cyclization , Molecular Structure , Sulfonamides/chemistryABSTRACT
A series of phenoxy linked bisquinoline derivatives were synthesised from the Friedlander annulation of 2-(4-acetylphenoxy)-1-aryl-1-ethanones with 2-aminobenzophenone in good yields using (±)-camphor-10-sulfonic acid (CSA) as the catalyst. These compounds were screened for their in vitro activity against Mycobacterium tuberculosis H37Rv (MTB) and among the 23 compounds screened, 2-(3-bromophenyl)-6-chloro-3-[4-(6-chloro-4-phenyl-2-quinolyl)phenoxy]-4-phenylquinoline (3q) and 2-(4-bromophenyl)-6-chloro-3-[4-(6-chloro-4-phenyl-2-quinolyl)phenoxy]-4-phenylquinoline (3o) were found to be the most active compounds with MIC of 1.1 and 2.2 µM against MTB. The cytotoxic effects against mouse fibroblasts (NIH 3T3) in vitro were evaluated for 3o and 3q, which displayed no toxic effects against mouse fibroblast cell line NIH 3T3.
Subject(s)
Antitubercular Agents , Camphor/analogs & derivatives , Chemistry Techniques, Synthetic , Mycobacterium tuberculosis/drug effects , Phenols/chemistry , Quinolines/chemistry , Animals , Antitubercular Agents/chemical synthesis , Antitubercular Agents/pharmacology , Camphor/chemistry , Catalysis , Mice , Microbial Sensitivity Tests , Molecular Structure , Phenols/chemical synthesis , Quinolines/chemical synthesis , Structure-Activity RelationshipABSTRACT
The synthesis of 2-(1H-pyrrolo[2,3-b]pyridin-3-yl)quinolines by a SnCl(2)-catalyzed multicomponent reaction has been described. The reaction proceeds chemo- and regioselectively in an atom-economic way, generating a library of 24 quinoline derivatives.
Subject(s)
Chemistry Techniques, Synthetic/methods , Imines/chemistry , Quinolines/chemistry , Quinolines/chemical synthesis , Tin Compounds/chemistry , CatalysisABSTRACT
A series of mono and bis-1,2,3-selenadiazole derivatives have been synthesized by the oxidative cyclization of mono and bis semicarbazones of 2-(3-oxo-1,3-diarylpropyl)-1-cyclohexanones using selenium(IV) oxide. The newly synthesized compounds were evaluated for their in vitro antimicrobial activity against Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 11632) and Candida albicans (ATCC 90028) and in vitro antituberculosis activity against Mycobacterium tuberculosis H37Rv (MTB). Among these compounds, 1,3-di(4-chlorophenyl)-3-(4,5,6,7-tetrahydro-1,2,3-benzoselenadiazol-4-yl)-1-propanone (2h) and 3-(4-chlorophenyl)-1-(4-methylphenyl)-3-(4,5,6,7-tetrahydro-1,2,3-benzoselenadiazol-4-yl)-1-propanone (2g) were found to be the most active compounds with MIC of 3.3 and 3.5 µM respectively against MTB.
Subject(s)
Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/pharmacology , Azoles/chemical synthesis , Azoles/pharmacology , Chemistry Techniques, Synthetic , Anti-Bacterial Agents/chemistry , Azoles/chemistry , Candida albicans/drug effects , Microbial Sensitivity Tests , Mycobacterium tuberculosis/drug effectsABSTRACT
A series of 3-heteroarylthioquinoline derivatives has been synthesized by the Friedlander annulation of 2-[(5-methyl-1,3,4-thiadiazol-2-yl)sulfanyl]-1-aryl-1-ethanone/2-(1,3-benzothiazol-2-ylsulfanyl)-1-aryl-1-ethanone/1-aryl-2-[(2-phenyl-2H-1,2,3,4-tetraazol-5-yl)sulfanyl]-1-ethanone with 2-aminobenzophenone in good yields using YbCl(3) as the catalyst. These compounds have been screened for their in vitro activity against Mycobacterium tuberculosis H37Rv (MTB) and among the 21 compounds screened, 2-[2-(4-bromophenyl)-4-phenyl-3-quinolyl]sulfanyl-5-methyl-1,3,4-thiadiazole (5d) and 2-[2-(4-chlorophenyl)-4-phenyl-3-quinolyl]sulfanyl-5-methyl-1,3,4-thiadiazole (5c) were found to be the most active compounds with MIC of 3.2 and 3.5 µM respectively against MTB. The cytotoxic effects against mouse fibroblasts (NIH 3T3) in vitro were evaluated for 5c and 5d, which displayed no toxic effects (IC(50) > 1000 µM) against the mouse fibroblast cell line NIH 3T3.
Subject(s)
Antitubercular Agents/chemistry , Antitubercular Agents/pharmacology , Mycobacterium tuberculosis/drug effects , Quinolines/chemistry , Quinolines/pharmacology , Thiadiazoles/chemistry , Thiadiazoles/pharmacology , Animals , Antitubercular Agents/chemical synthesis , Humans , Mice , Microbial Sensitivity Tests , Models, Molecular , NIH 3T3 Cells , Quinolines/chemical synthesis , Structure-Activity Relationship , Thiadiazoles/chemical synthesis , Tuberculosis/drug therapyABSTRACT
A simple and efficient protocol for the construction of substituted piperazines, piperidines, thiomorpholines, decahydroquinolines, perhydrocyclopenta[b]pyridine, and pyrrolidines bearing N-hydroxy substituents through intramolecular reductive cyclization of diketoximes using sodium cyanoborohydride is described.
Subject(s)
Chemistry, Pharmaceutical , Morpholines/chemical synthesis , Piperazines/chemical synthesis , Piperidines/chemical synthesis , Pyridines/chemical synthesis , Pyrrolidines/chemical synthesis , Quinolines/chemical synthesis , Borohydrides/chemistry , Cyclization , Molecular Structure , Oximes/chemistry , StereoisomerismABSTRACT
Azines derived from substituted phenacyl aryl/cyclohexyl sulfide on treatment with excess phosphorous oxychloride in N,N-dimethylformamide have been found to yield two isomeric pyrazoles in each case. A plausible mechanism has been suggested for the formation of the products. The antimycobacterial activity of the isomeric compounds has been tested against Mycobacterium tuberculosis (MTB).
Subject(s)
Anti-Bacterial Agents/chemical synthesis , Pyrazoles/pharmacology , Sulfides/pharmacology , Anti-Bacterial Agents/pharmacology , Antitubercular Agents/chemistry , Antitubercular Agents/pharmacology , Dimethylformamide , Formamides/chemistry , Microbial Sensitivity Tests , Mycobacterium tuberculosis/drug effects , Pyrazoles/chemistry , Sulfides/chemistryABSTRACT
A new set of highly substituted pyridine derivatives has been synthesized by a product selective four component reaction of aryl aldehyde, malononitrile and 2-aryl/cyclohexylsulfanyl-1-aryl-1-ethanones in presence of sodium hydroxide in methyl/ethyl alcohol. Among the compounds, 4,6-bis(4-chlorophenyl)-5-[(4-chlorophenyl)sulfanyl]-2-methoxynicotinonitrile (4n) inhibited Mycobacterium tuberculosis (MTB) with minimum inhibitory concentration (MIC) of 3.1 microM and was more potent than ethambutol and pyrazinamide.