Synthesis and Pharmacological Use of 10H-Phenothiazines,Their Sulfones,and Ribofuranosides

This article describes the synthesis of 10H-phenothiazines from 2-aminobenzenethiol and o-halonitrobenzenes via Smiles rearrangement. Upon refluxing with hydrogen peroxide in glacial acetic acid, these phenothiazines yield the corresponding 10H-phenothiazine-5,5-dioxides. The phenothiazines have also been used as base to prepare ribofuranosides by the reaction with β-D-ribofuranose-1-acetate-2,3,5-tribenzoate. All the synthesized compounds have been characterized by spectral and elemental analysis and have been examined for antioxidant and antimicrobial activity.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Synthesis and biological activity of substituted 3-fluoro/3-trifluoromethyl 10H-phenothiazines, its ribofuranosides and sulfones

The present article describes the synthesis of new fluorinated 10H-phenothiazines by Smiles rearrangement. The reaction of these synthesized phenothiazines with sugar (beta-d-ribofuranose 1-acetate-2,3,5-tribenzoate) afforded the new ribofuranosides and the oxidation of these synthesized phenothiazines with 30% hydrogen peroxide in glacial acetic acid resulted in the formation of 10H-phenothiazine sulfones. These compounds were evaluated for their antioxidant and antimicrobial activities (using broth microdilution method). The structural assignments of the synthesized compounds were made on the basis of elemental analysis and spectroscopic data.     

Design,Synthesis, and Biological Screening of Novel Anthranilic Diamides

Three series of new anthranilic diamide derivatives containing sulfide, N‐cyanomethylsulfilimine, and N‐cyanomethylsulfoximine groups were designed and synthesized by combining the active substructures of anthranilic diamides and sulfoxaflor. The structures of all newly synthesized compounds were confirmed by IR and ¹H/¹³C‐NMR, and some of them were confirmed by elemental analysis or HRMS too. The synthesized compounds were screened for their insecticidal and fungicidal activities. Bioasssay results indicated that some of the synthesized compounds possessed certain degrees of insecticidal activity against Mythimna separata. However, some compounds exhibited good fungicidal activity against Sclerotinia sclerotiorum.     

Synthesis and Antimicrobial Studies of New Spiropyran Quinazolinone Derivatives with Amide,Urea, and Sulfonamide Moieties

Three new series of quinazolinone derivatives containing amide, urea, and sulfonamide were synthesized through multistep synthesis. The required intermediates 4‐[(4′‐oxo‐2,3,3′,4′,5,6‐hexahydro‐1′H ‐spiro[pyran‐4,2′‐quinazolin]‐1′‐yl)methyl]benzoic acid 4 and 1′‐(3‐aminobenzyl)‐2,3,5,6‐tetrahydro‐1′H ‐spiro[pyran‐4,2′‐quinazolin]‐4′(3′H )‐one 8 were prepared by hydrolysis of ester and reduction of nitro intermediates. Three different series of compounds were synthesized from these two scaffolds. The key scaffolds 4 and 8 were successfully converted to target molecules via amides 5a – k , urea 9a – f , and substituted sulfonamides 10a – e . The chemical structures of newly synthesized compounds were characterized by spectral analysis. The structure of 5d was confirmed by X‐ray crystallography study. These newly synthesized compounds were screened for antibacterial studies against Staphylococcus epidermidis , Salmonella typhi , Proteus mirabilis , and Shigella sonnei and for the antifungal activity against Aspergillus niger and Candida albicans . Among all the compounds, 9b – d showed excellent activities against S. typhi . Compound 9a showed moderate activity against all fungi stains, and 5I showed moderate activity against P. mirabilis , while the other derivatives showed fairly good activities.     

Synthesis,Structure, and Biological Activities of 10‐Substituted 3,3,6,6‐Tetramethyl‐9‐Aryl‐3,4, 6,7,9,10‐hexahydroacridine‐1,8(2H,5H)‐dione Derivatives

A series of 10‐substituted‐3,3,6,6‐tetramethyl‐9‐aryl‐3,4,6,7,9,10‐hexahydroacridine‐1,8(2H ,5 H )‐dione derivatives 2 were synthesized by reaction of compounds 1 with amines. The compounds 1 were effectively prepared by 5,5‐dimethylcyclohexane‐1,3‐dione and aldehydes in the presence of a little amount of L‐proline as catalyst at room temperature. All the compounds were characterized by IR, MS, and ¹H NMR. The crystal data of 1b and 2d were collected by X‐ray single‐crystal diffraction, and compounds 2b and 2d exhibited better inhibitory activity against HepG2 cells.     

Synthesis,Characterization, and Biological Evaluation of Novel 3‐(4‐Chlorophenyl)‐2‐(substituted)quinazolin‐4(3H)‐one Derivatives as Multi‐target Anti‐inflammatory Agents

A novel class of 3‐(4‐chlorophenyl)‐2‐(substituted)quinazolin‐4(3H)‐one derivatives were synthesized, and the structure of synthesized compounds was characterized by IR, ¹H NMR, and mass spectroscopy. The newly synthesized compounds ( 4a–g and 6a–g ) were tested for their in vitro cyclooxygenase (COX) inhibition activity. The compounds have inhibitory profile against both COX‐1 and COX‐2, and some of the compounds are found to be selective against COX‐2. The compound 6g showed distinct inhibitory activity on COXs. The synthesized compounds were evaluated for their potential anti‐inflammatory activity as inhibitors of the proinflammatory cytokines IL‐6. Compounds 4d – g showed the highest level of inhibition among all the tested compounds. Thus, our data suggested that these compounds may represent a new class of potent anti‐inflammatory agents.     

Derivational,Structural, and Biological Studies of Some New Pyrazolyl,Isoxazolyl, Pyrimidinyl,Pyridazinyl, and Pyridopyridazinyl from 4‐Substituted Antipyrine

(1,5‐Dimethyl‐3‐oxo‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐4‐yl)carbono‐hydrazonoyl dicyanide was used as a key intermediate for the synthesis of novel pyrazole, isoxazole, pyrimidine, and pyridazine derivatives. The newly synthesized compounds were characterized by elemental analyses and spectral data (IR, ¹H‐NMR, ¹³C‐NMR, and mass spectra). The compounds were tested for their in vitro antibacterial activity against Gram‐positive bacteria as (Staphylococcus aureus and Bacillus subtilis ) and Gram‐negative bacteria (Pseudomonas aeruginosa and Escherichia coli ). The investigated compounds were tested against two strains of fungi Botrytis fabae and Fusarium oxysporum using diffusion agar technique. The biological results showed clearly that most of the synthesized compounds revealed mild to moderate activity against the used microorganisms.     

Synthesis and Antimicrobial Evaluation of Novel Polyfused Heterocycles‐Based Quinolone

Syntheses of some new heterocyclic compounds incorporating quinolone moieties were achieved via reaction of 4‐hydroxy‐7‐methoxyquinolin‐2(1H)‐one ( 1 ) or 3‐bromo‐4‐hydroxy‐7‐methoxyquinolin‐2(1H)‐one ( 2 ) with binucleophilic reagents. The newly synthesized compounds were characterized by elemental analyses and spectral data (IR, ¹H‐NMR and mass spectra). The newly synthesized compounds were screened for their antibacterial activity against Gram‐positive bacteria (Bacillus thuringiensis) and Gram‐negative bacteria (Escherichia coli). The results showed clearly that compounds 1 and 3 are the more potent antibacterial agents against E. coli, compounds 4 , 5 , 6 and 8 , 9 , 10 , 11 , 12 , 13 exhibited moderate activities against E. coli strain, and compounds 7 and 11 exhibited weak activities compared with Gentamicin as a well known standard drug.     

Pyrido[1,2‐a]pyrimidin‐4‐ones: Ligand‐based Design,Synthesis, and Evaluation as an Anti‐inflammatory Agent

In the present study, a series of novel pyrido[1,2‐a]pyrimidin‐4‐one derivatives ( 1 – 45 ) were synthesized, characterized, and evaluated for their anti‐inflammatory activity. The structures of all newly synthesized compounds were confirmed by ¹H NMR, ¹³C NMR, mass spectroscopy, and C, H, and N analyses. Preliminary these newly synthesized compounds were evaluated for their in vitro cyclooxygenase (COX)‐2/COX‐1 inhibitory activity. The celecoxib, a COX‐2 inhibitor, was used as a reference standard drug. In this inhibitory study, compounds 42 , 43 , 44 , and 45 were found to have significant in vitro inhibitory profile as compared with the reference drug. These compounds were then subjected to their in vivo anti‐inflammatory assay by using carrageenan‐induced rat paw edema method in next level of screening. Later, these same compounds were tested for their ulcerogenic property. Based on these activity data, the compound 43 (in vitro COX‐2 activity—IC₅₀ = 0.4 μM, SI = 400, in vivo anti‐inflammatory activity—72% inhibition after 3 h, and 0.38%—Ulcer index) was emerged as most promising anti‐inflammatory agent with very low ulcerogenic action.     

Synthesis of New Benzoxazinone,Quinazolinone, and Pyrazoloquinazolinone Derivatives and Evaluation of Their Cytotoxic Activity Against Human Breast Cancer Cells

Synthesis of 2‐[3‐(3,4‐dichlorophenyl)‐3‐oxoprop‐1‐enyl]‐4H‐benzo[3,1]oxazin‐4‐one 2 as a precursor to synthesize quinazolinones 5 , 7 pyrazolylquinazolinones, 4 , 12 , 13 , 14 , 16 benzothiazine thione 10 , benzene derivative 3 pyrroloquinazolinone 6 , benzoimidazoquinazolinone 8 , and pyrazolotriazepinoquinazolinone 15 . The structures of the newly synthesized compounds were established by their elemental analyses and spectral data. Most of the synthesized compounds exhibited high antitumor and cytotoxic activity against human breast cancer cells.     

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.     

Synthesis and Antimicrobial Activity of Some Novel Quinoline,Chromene, Pyrazole Derivatives Bearing Triazolopyrimidine Moiety

7‐Amino‐3‐phenyl‐[1,2,4]triazolo [4,3‐a] pyrimidin‐5(1H )‐one ( 5 ) was utilized as key intermediate for the synthesis of some new, quinolines 9 , 10 , 11 , 12 , 13 , 14 and 18 , 19 , 20 , acrylonitrile 25 and 28 , coumarin 26 , and pyrazoles 31 , 32 , 33 , 34 incorporating triazolopyrimidines. The structures of the newly synthesized compounds were confirmed by elemental analysis, IR, ¹H NMR, and mass spectral data. Representative compounds of the synthesized products were tested and evaluated as antimicrobial. Compounds 25 , 28 , 31 , 32 , 33 , and 34 are the most promising.     

Synthesis,antimicrobial, and antioxidant activities of new pyridyl‐ and thiazolyl‐bearing carbohydrazides

A series of novel substituted (E)‐N′‐benzylidene‐4‐methyl‐2‐(2‐propylpyridin‐4‐yl)thiazole‐5‐carbohydrazide derivatives ( 6a‐l ) have been synthesized by following the multistep synthetic route starting from prothionamide. The resulting compounds were characterized via ¹H, ¹³C NMR, and HRMS spectral data. The synthesized carbohydrazides were evaluated for their in vitro antimicrobial and antioxidant activities. Tested molecules have displayed moderate to good growth inhibition activity. Among the screened compounds, 6b , 6e , 6j, and 6k are found to be the more promising antimicrobial agents. A 2,2‐diphenyl‐1‐picrylhydrazyl assay was used to test the antioxidant activity of the carbohydrazides. The carbohydrazide derivatives 6b and 6i have shown better free‐radical scavenging ability than the other investigated compounds.     

A Versatile Synthesis,PM3‐Semiempirical,Antibacterial, and Antitumor Evaluation of Some Bioactive Pyrazoles

This research work describes the synthesis and biological properties of some novel isolated or fused heterocyclic ring systems with pyrazole, for example; enaminones containing pyrazolone ring photochromic functional unit, 4‐[(4‐chlorophenylamino)methylene]‐3‐methyl‐1‐phenyl‐1H‐pyrazol‐5(4H)‐one (3) and some analogous derivatives 4, 9, and 10, also as pyrazolo[3,4‐b]pyridine, pyrazolo[3,4‐b]quinoline, pyrazolo[3′,4′:4,5]thieno[2,3‐c]pyrazoline and pyrazolo[3,4‐c]pyrazole were synthesized and characterized. Newly synthesized compounds were characterized by IR, ¹H NMR, ¹³C NMR, mass spectral data and quantum mechanical calculations. Selected products were tested for their antibacterial and antitumor agents.     

Novel 1,3,4‐Oxadiazole Derivatives of Dihydropyrimidinones: Synthesis,Anti‐Inflammatory,Anthelmintic, and Antibacterial Activity Evaluation

The present study depicts synthesis of a series of some novel 5‐(5‐(aryl)‐1,3,4‐oxadiazol‐2‐yl)‐3,4‐dihydro‐6‐methyl‐4‐styrylpyrimidin‐2(1H)‐one derivatives. All the newly synthesized compounds were characterized by FTIR, ¹H NMR, ¹³C NMR, mass spectrometry, and elemental analysis. The compounds were evaluated for their in vivo anti‐inflammatory activity by the carrageenan‐induced rat paw edema method. The compounds were also screened for their anthelmintic activity on Indian earthworms and antibacterial activity against some gram positive and gram negative strains of bacteria. This pharmacological activity evaluation revealed that, among all the compounds screened, compounds 4b and 4c were found to have promising anti‐inflammatory activity. Interestingly, compounds 4b , 4c , and 4i exhibited appreciable anthelmintic property, while compounds 4c , 4g , and 4h showed leading antibacterial activity against the selected pathogenic strains of bacteria.     

Glycerol Mediated Synthesis,Biological Evaluation,and Molecular Docking Study of 4‐(1H‐pyrazol‐4‐yl)‐polyhydroquinolines as Potent Antitubercular Agents

A series of 4‐(1H‐pyrazol‐4‐yl)‐polyhydroquinolines were synthesized through one‐pot four‐component Hantzsch condensation of 1,3‐diphenyl‐1H‐pyrazole‐4‐carbaldehydes, ammonium acetate, dimedone, and alkyl acetoacetate in glycerol as a green reaction medium. The structures of the compounds are verified by spectroscopic methods and screened for their antimicrobial activity against Mycobacterium tuberculosis H37RV strain. Almost all the synthesized derivatives reveal excellent antitubercular activity based on minimum inhibitory concentration. Especially the compounds 5h and 5k exhibit outstanding antitubercular activity with minimum inhibitory concentration 1.6 μg/mL. In addition, molecular docking study of synthesized scaffolds against enoyl‐acyl carrier protein reductase from M. tuberculosis was performed to propose the binding modes.     

Synthesis,Characterization, Aggregation Properties,Antioxidant and Antimicrobial Activity of Novel Unmetalled and Metallophthalocyanines Bearing Coumarin Derivatives

In this study, novel Metal–free and metallophthalocyanines 3–10 were prepared by the cyclotetramerization of the new phthalonitriles 1–2 and the corresponding divalent metal salts. The novel phthalonitrile derivatives 1–2 were synthesized by the reaction between 4‐nitrophthalonitrile with 3‐hydroxycoumarin and 7‐hydroxycoumarin respectively in DMF in the presence of dry K₂CO₃ as base catalyst. The aggregation behavior of these compounds was investigated in different concentrations of DMSO for the Zn and Co phthalocyanines 5 , 9. In vitro antioxidant test method, namely diphenylpicrylhydrazyl radical scavenging activity, was used to determine the antioxidant activity of complexes 5–10 . In addition, these compounds were analyzed for their antibacterial activity against some bacteria by using the disk‐diffusion method. The compounds were characterized by spectral data (IR, UV–Vis, ¹H‐NMR and mass spectroscopies) as well as elemental analysis.     

Synthesis,Characterization, and Antibacterial Activity of Novel (1H‐Benzo[d]imidazole‐2‐yl)‐6‐(diethylamino)‐3H‐one‐xanthene,Phenoxazine, and Oxazine

A series of novel (1H‐benzo[d]imidazole‐2‐yl)‐6‐(diethylamino)‐3H‐one‐xanthene, phenoxazine, and oxazine derivatives have been synthesized from 2‐(2′,4′‐dihydroxyphenyl) benzimidazole intermediate. Synthesized compounds 8a , 8b , 8c , 8d are fluorescent in solution, photophysical properties of compounds were studied and results revealed that compounds absorb and emit in UV–visible region with good fluorescence quantum yield. Synthesized compounds are thermally stable up to 300°C. The antibacterial activities of the synthesized compounds were studied by the well‐diffusion method. Escherichia coli (ATTC‐25922), Staphylococcus aureus (ATCC‐25923), Micrococcus (ATCC‐4698), and Bacillus subtilis (ATCC‐55422) were used to investigate the antibacterial activities.     

Synthesis,Docking, ADME‐Tox Study of 2‐(2‐(2‐Chlorophenyl)quinoline‐4‐carbonyl)‐N‐substituted hydrazinecarbothioamide Derivatives and Their Biological Evaluation

A series of 2‐(2‐(2‐chlorophenyl)quinoline‐4‐carbonyl)‐N‐substituted hydrazinecarbothioamide derivatives were synthesized by facile and efficient conventional method. The structures of the compounds were elucidated with the aid of an elemental analysis, IR, ESI‐MS, ¹H‐NMR, and ¹³C‐NMR spectral data. The synthesized compounds were evaluated for their in vitro antibacterial, antifungal, antimalarial, and antituberculosis activity against standard drugs. The bacterial studies were determined against gram‐positive and negative bacteria. These compounds were found to a broad spectrum of activity against the screened bacteria, but poor activity was observed against Pseudomonas aeruginosa and Escherichia coli. Compounds 8d , 8f , 8i , 8l , and 8n showed the potent activity against Staphylococcus aureus. Compounds 8d , 8g , 8k , 8l , and 8q show the potent activity against antimalarial as compared with the standard drugs Chloroquine, Quinine and compounds 8h , 8n , and 8o shows mild activity against H37Rv strain. Molecular docking revealed that synthesized derivatives and target proteins were actively involved in a binding pattern and had a significant corelation with biological activity. We have also performed a molecular dynamics and ADME‐Tox parameters for the synthesized compounds.     

Synthesis and Antioxidant Evaluation of Some Novel Thiophene,Pyrazole, Chromene,Pyrazolotriazine Derivatives Bearing Sulfonamide Moiety

As a part of ongoing studies in developing new potent antioxidant agents, N‐[4‐(aminosulfonyl)phenyl]‐2‐cyanoacetamide ( 3 ) was utilized as key intermediate for the synthesis of some new thiophene, chromene, and pyrazolotriazine pyridine derivatives. The structures of the newly synthesized compounds were confirmed by elemental analysis, IR, ¹H‐NMR, and mass spectral data. Representative compounds of the synthesized products were tested and evaluated as antioxidant. Compounds 7 and 30 are promising compounds.