Synthesis and Antimicrobial Activity of 2-Substituted-3-((3-(6-Nitrobenzo[D]thiazol-2-yl)-4-oxo-3,4-Dihydroquinazolin-2-yl)Methyl)-1,3,4-thiadiazol-3-ium-5-thiolate

Abstract

A new series of 2-substituted-3-((3-(6-nitrobenzo[d]thiazol-2-yl)-4-oxo-3,4-dihydroquinazolin-2-yl)methyl)-1,3,4-thiadiazol-3-ium-5-thiolate 6(a–j) was synthesized starting from anthranilic acid 1. The structures of the newly synthesized compounds were characterized by IR, ¹H NMR, ¹³C NMR, mass spectra, and elemental analysis. The final compounds were tested for their antimicrobial activity against several microbes.

[Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional text and tables.]     

2-(Benzo[d]thiazol-2-yl) phenyl-4-nitrophenyl alkyl/aryl substituted phosphoramidates: Synthesis,characterization and antimicrobial activity evaluation

A series of new 2-(benzo[d]thiazol-2-yl) phenyl-4-nitrophenyl alkyl/aryl substituted phosphoramidate derivatives (7a-j) of biological interest are synthesized in two steps via an in situ process without the isolation of the intermediate. 2-(Benzo[d]thiazol-2-yl) phenol (3) was treated with 4-nitrophenyl phosphorodichloridate(4) to obtain the monochloro intermediate, 2-(benzo[d]thiazol-2-yl)phenyl (4-nitrophenyl) phosphorochloridate(5). It was subsequently reacted with various amines, 6(a-j) to afford the desired title products. IR, NMR (¹H, ¹³C and ³¹P), mass spectral and elemental analysis are used to characterize the structures of the newly synthesized compounds. The antibacterial and antifungal activities are determined by the growth of inhibition of bacteria and fungi of the title compounds at two concentrations, 50 and 100 µg/mL, and minimum inhibitory concentrations to the active compounds. The compounds 7e, 7f and 7j exhibited promising inhibition activity against bacterial strains and 7c, 7e and 7i against A. niger and C. albicans and MIC values are in the range of 10.0–15.0 µg/mL.     

Synthesis and microbial screening of 8-(benzyloxy)-5-(2-[1,3-diphenyl-1H-pyrazol-4-yl]thiazol-4-yl)quinolin-2(1H)-one derivatives

The present investigation describe the synthesis of 8-(benzyloxy)-5-(2-[1,3-diphenyl-1H-pyrazol-4-yl]thiazol-4-yl)quinolin-2(1H)-one derivatives. Quinolin-8-ol was transformed by five step synthetic procedures into 8-Benzyloxy-5-(2-bromo-acetyl)-1H-quinolin-2-one. Subsequently, 8-Benzyloxy-5-(2-bromo-acetyl)-1H-quinolin-2-one condensed with 1,3-Diphenyl-1H-pyrazole-4-carbothioic acid amide in the presence of acetonitrile to afford 8-(benzyloxy)-5-(2-[1,3-diphenyl-1H-pyrazol-4-yl]thiazol-4-yl)quinolin-2(1H)-one derivatives. Synthesized compounds were screened for their antimicrobial activity against gram-positive and gram-negative bacteria. Most of the synthesized compounds are found to be active against tested bacterial strains and fungal strain.     

Synthesis and Antimycobacterial Activity of New 2-Hydroxy- N -(3-oxo-1-thia-4-azaspiro[4.4]non-4-yl)/(3-oxo-1-thia-4-azaspiro[4.5]dec-4-yl)-2,2-diphenylacetamide Derivatives

2-Hydroxy-2,2-diphenylacetohydrazide (2), cyclic ketones, and mercaptoalkanoic acids were converted into 2-hydroxy-N-(3-oxo-1-thia-4-azaspiro[4.4]non/[4.5]dec-4-yl)-2,2-diphenylacetamide derivatives (3, 4) in a one pot procedure. Compounds 3 and 4 were tested for in vitro antimycobacterial activity against M. tuberculosis H37Rv. The compounds were found to provide 0–86% inhibition of mycobacterial growth in the primary screen conducted at 6.25 μg/cm³.     

Synthesis and Antimycobacterial Activity of New 2-Hydroxy-N-(3-oxo-1-thia-4-azaspiro[4.4]non-4-yl)/(3-oxo-1-thia-4-azaspiro[4.5]dec-4-yl)-2,2-diphenylacetamide Derivatives

Summary. 2-Hydroxy-2,2-diphenylacetohydrazide (2), cyclic ketones, and mercaptoalkanoic acids were converted into 2-hydroxy-N-(3-oxo-1-thia-4-azaspiro[4.4]non/[4.5]dec-4-yl)-2,2-diphenylacetamide derivatives (3, 4) in a one pot procedure. Compounds 3 and 4 were tested for in vitro antimycobacterial activity against M. tuberculosis H37Rv. The compounds were found to provide 0–86% inhibition of mycobacterial growth in the primary screen conducted at 6.25 μg/cm³.     

Synthesis,characterization and antibacterial activity of 1-([6-bromo-2-hydroxy-naphthalen-1-yl]arylphenyl)methyl)-3-chloro-4-(arylphenyl)-azetidin-2-one

One-pot synthesis of 1-([6-bromo-2-hydroxy-naphthalen-1-yl]-aryl-phenyl)methyl)-3-chloro-4-(aryl-phenyl)azetidin-2-ones has been reported in the present research work via Staudinger [2 + 2] ketene-imine cycloaddition reaction pathway. The reaction of 1-((Benzylideneamino)(aryl)methyl)-6-bromo-naphthalen-2-ols with chloroacetic acid and triethylamine afforded 1-([6-bromo-2-hydroxynaphthalen-1-yl]aryl-phenyl)methyl)-3-chloro-4-(aryl-phenyl)azetidin-2-ones. For the structural elucidation of series of compounds, different analytical and spectroscopic techniques such as elemental analysis, IR spectra, ¹H-NMR spectra and mass spectra were used. All the newly synthesized compounds were tested for their anti-bacterial activity studies. It revealed that some of the compounds possesses moderate to good activities as compared to standard drugs. The widest spectrum of anti-bacterial activities against both gram-positive and gram-negative bacterial strains among the examined compounds possessed having more hydroxyl group along with β-lactam ring compared to other substituted azetidinones.     

1-[5-(1,3-二氧-4,5,6,7-四氢-1H-异吲哚-2-基)苯基]-3-取代脲衍生物的合成与除草活性研究

为了寻找高效低毒的原卟啉原氧化酶抑制剂(protox)类除草剂, 设计并合成了一系列1-[5-(1,3-二氧-4,5,6,7-四氢-1H-异吲哚-2-基)苯基]-3-取代脲类衍生物4a～4d和5a～5g. 化合物4a～4d经异氰酸酯法合成, 收率、纯度高; 化合物5a～5g利用固体光气一锅法合成, 反应时间短.所得化合物结构经¹H NMR, IR, 质谱和元素分析表征. 初步生物活性测试表明: 化合物4c, 5a, 5b, 5c在有效成分75 g/hm² 剂量下对苘麻、马刺苋、凹头苋等双子叶杂草表现出90%以上的防效.     

N-{4-{N-甲基-N-[2-羟基-3-(2,4-二氧代-1,2,3,4-四氢嘧啶-5-基)氨基]丙基}氨基-3-溴}苯甲酰基-L-谷氨酸二乙酯及其衍生物的合成

报道了N-{4-{N-甲基-N-[2-羟基-3-(2,4-二氧代-1,2,3,4-四氢嘧啶-5-基)氨基]丙基}氨基-3-溴}苯甲酰基-L-谷氨酸二乙酯及其衍生物的简便合成方法. 分别以4-氨基苯甲酸乙酯和4-氨基苯甲酰基-L-谷氨酸二乙酯为起始物, 经甲基化、烯丙基化、溴羟基化、环氧化、开环、脱保护等反应首次合成了6个新型5-取代氨基嘧啶类化合物, 并通过¹H NMR, ¹³C NMR 和MS对其化学结构进行了表征. 初步生物活性结果表明, 苯环侧链的L-谷氨酸酯部分是此类化合物抑制人重组二氢叶酸还原酶的必需结构.     

Synthesis,anticancer, and computational studies of 1, 3, 4-oxadiazole-purine derivatives

Theophylline-7-acetic acid (acefylline) ( 3 ) and its derivatives are pharmacologically active compounds and generally recognized as bronchodilators for the treatment of respiratory diseases like acute asthma for over 70 years. In this article, synthesis of 2-((5-((1,3-dimethyl-2,6-dioxo-2,3-dihydro-1H-purin-7(6H)-yl)methyl)-1,3,4-oxadiazol-2-yl)thio)-N-arylacetamides ( 10a-j ) has been reported. All the synthesized derivatives ( 10a-j) were structurally verified by FT-IR, ¹H NMR, ¹³C NMR and evaluated for their anti-cancer (using MTT assay), hemolytic and thrombolytic potential. N-(4-Chlorophenyl)-2-(5-((1,3-dimethyl-2,6-dioxo-2,3-dihydro-1H-purin-7(6H)-yl)methyl)-1,3,4-oxadiazol-2-ylthio)acetamide ( 10g ) was found to be the most active against human liver cancer cell lines (Huh7) having cell viability 53.58 ± 1.28 using 100 μg/mL concentration of compound which was further in-silico modelled to describe the possible mechanistic insights for its anti-proliferative activity. The results of hemolytic and thrombolytic activities indicated that these derivatives were less toxic and hold considerable potential as a drug candidate. 2-(5-((1,3-Dimethyl-2,6-dioxo-2,3-dihydro-1H-purin-7(6H)-yl)methyl)-1,3,4-oxadiazol-2-ylthio)-N-(2-fluorophenyl)acetamide ( 10c ) of the series was found to be least toxic with 0.1% hemolysis relative to ABTS (95.5%) as positive control. 2-(5-((1,3-Dimethyl-2,6-dioxo-2,3-dihydro-1H-purin-7(6H)-yl)methyl)-1,3,4-oxadiazol-2-ylthio)-N-(tetrahydro-2H-pyran-4-yl)acetamide ( 10j ) exhibited potent clot lysis activity (90%) as compared to negative control DMSO (0.57%).     

Synthesis of (s)-1-{3-[4-(4-benzo[d]isothiazol-3-yl-piperazin-1-yl)-3-fluoro-phenyl]-2-oxo-oxazolidin-5-ylmetyl}-3-substituted-urea derivatives as antibacterial agents

A new series of (s)-1-{3-[4-(4-benzo[d]isothiazol-3-yl-piperazin-1-yl)-3-fluoro-phenyl]-2-oxo-oxazolidin-5-ylmetyl}-3-substituted-urea derivatives have been synthesized and characterized with spectral data, such as IR, NMR and Mass spectroscopies. All compounds are in vitro evaluated for their efficacy as antimicrobial agent against the gram-positive pathogenic strains such as Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis ATCC 12228 and Streptococcus pyogens ATCC 8668. Five compounds ( 19k , 19l , 19m , 19n and 19o ) out of 15 compounds showed moderate activity.     

Synthesis of diverse (E)-2-((1H-imidazol-1-yl)methyl)-2-((benzyloxy)methyl)-2,3-dihydro-1H-inden-1-one O-benzyl oxime derivatives as potent antileishmanial agents

A series of (E)-2-((1H-imidazol-1-yl)methyl)-2-((benzyloxy)methyl)-2,3-dihydro-1H-inden-1-one O-benzyl oximes ( 6a-j ) were prepared and evaluated for their in vitro antileishmanial potency against Leishmania donovani (in promastigote and amastigote models). At a concentration of 05-μg/mL, compounds 3a-d , 4a-d , 5a , 5b , 6a-d, and 7a-d exhibited 97% to 100% and 87% to 100% inhibition against promastigotes and amastigotes, respectively. Compounds 6a , 6d-6j and 6a , 6i , 6j exhibited equal antileishmanial potency to that of SSG and Pentamidin at lower values of IC₅₀.     

Molecular structures of methyl 4-[(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)methyl]-1-methyl-1H-pyrazol-5-carboxylate and methyl 4-[(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)methyl]-1-methyl-1H-pyrazol-3-carboxylate

The structure of methyl 4-[(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)methyl]-1-methyl-1H-pyrazol-5-carboxylate is determined by X-ray crystallography and further used to elucidate the structure of methyl 4-[(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)methyl]-1-methyl-1H-pyrazol-3-carboxylate, using the data of homo- and heteronuclear 2D NMR correlation spectroscopy.     

Ultrasound- and microwave-assisted synthesis of (E)-1-aryl-3-[2-(piperidin-1-yl)quinolin-3-yl]prop-2-en-1-ones and (E)-1-aryl-3-[2-(pyrrolidin-1-yl)quinolin-3-yl]prop-2-en-1-ones,and their antimicrobial activity

Series of new (E)-1-aryl-3-[2-(piperidin-1-yl)quinolin-3-yl]prop-2-en-1-ones and (E)-1-aryl-3-[2-(pyrrolidin-1-yl)quinolin-3-yl]prop-2-en-1-ones have been efficiently prepared via the Claisen-Schmidt condensation of 2-(piperidin-1-yl)quinoline-3-carbaldehyde and 2-(pyrrolidin-1-yl)quinoline-3-carbaldehyde, respectively, with aryl methyl ketones under conditions of ultrasound and microwave irradiation. Structures of the products have been confirmed by IR, ¹H NMR, ¹³C NMR, and mass spectroscopy, as well as by elemental analysis. Evaluation of the in vitro antibacterial activity against bacterial (Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli) and fungal (Aspergillus niger and Candida metapsilosis) strains has revealed good antimicrobial activity of some of the tested compounds.     

Studies on Antimicrobial Evaluation of Some 1-((1-(1H-Benzo[d]imidazol-2-yl)ethylidene)amino)-6-((arylidene)amino)-2-oxo-4-phenyl-1, 2-dihydropyridine-3,5-dicarbonitriles

A new series of 1-((1-(1H-benzo[d]imidazol-2-yl)ethylidene)amino)-6-((arylidene)amino)-2-oxo-4-phenyl-1,2-dihydropyridine-3,5-dicarbonitriles (4a–o) have been synthesized for the development of antimicrobial agents. Newly synthesized compounds were evaluated for their in vitro antibacterial activity against Gram-positive bacteria (Pseudomonas aeruginosa, Streptococcus pyogenes), Gram-negative bacteria (Escherichia coli, Staphylococcus aureus), and antifungal activity (Candida albicans, Aspergillus niger, Aspergillus clavatus). These compounds were characterized by infrared, ¹H NMR, ¹³C NMR, and mass spectra. The synthesized compounds 4b, 4e, 4 h, and 4k showed potent antimicrobial activity against tested microorganisms.     

Synthesis of 3-[4-(1-Benzofuran-2-yl)-1,3-thiazol-2-yl]-2-(4-aryl)-1,3-thiazolidin-4-one Derivatives as Biological Agents

A protocol for the synthesis of 3-[4-(1-benzofuran-2-yl)-1,3-thiazol-2-yl]-2-(4-aryl)-1,3-thiazolidin-4-one derivatives (5a–e) has been developed from 1-(1-benzofuran-2-yl)-2-bromoethanone (2),which served as a key intermediate for the synthesis of the title compounds. The reaction of compound 2 with thiourea furnished 4-(1-benzofuran-2-yl)-1,3-thiazol-2-amine 3, which upon further reaction with various aromatic aldehydes, gave Schiff bases 4a–e. These Schiff bases, when treated with thioacetic acid in the presence of catalytic amount of anhydrous ZnCl₂, yielded thiazolidinone derivatives 5a–e. All the newly synthesized compounds have been characterized by analytical and spectral data and screened for their antimicrobial and analgesic 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,Reactions, and Characterization of 6-Amino-4-(Benzo[b]Thiophen-2-YL)-2-Thioxo-1, 2-Dihydropyridine-3, 5-Dicarbonitrile

Abstract

Benzothiophene -2- carbaldehyde 1 reacted with 2-cyanoethanethioamide 2 in 1:2 molar ratios to give the corresponding 6-amino-4-(benzo[b]thiophen-2-yl)-2-thioxo-1, 2-dihydropyridine-3,5-dicarbonitrile 6. The synthetic potentiality of compound 6 was investigated via its reaction with active halogen-containing reagents to afford the corresponding thieno[2,3-b]pyridine derivatives 11a,b, 14, 16, and 19. Also, compound 6 reacted with hydrazine hydrate to give the pyrazolo[3,4-b]pyridine derivative 21. Compound 21 condensed with 4-(2-thienyl)benzaldehyde to afford pyrazolo[3,4-b]pyridine derivative 23. Structural elucidation of all the newly synthesized heterocyclic compounds was based on elemental analyses, IR, ¹H NMR, and mass spectra.

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 of 1-[3-methyl-2(3H)-benzazolon-5- or 6-yl]-4-{4-[cis-2-(2,4-dichlorophenyl)-2-(1H-imidazol-1-yl-methyl)-1,3-dioxolan-4-yl]methyleneoxyphenyl}piperazines

Reactions of 3-methyl-6-[4-(4-hydroxyphenyl)-1-piperazinyl]-2(3H)-benzoxazolone, 3-methyl-6-[4-(4-hydroxy-phenyl)-1-piperazinyl]-2(3H)-benzothiazolone and 1,3-dimethyl-5-[4-(4-hydroxyphenyl)-1-piperazinyl]-2(3H)-benzimidazolone with cis-{[2-(2,4-dichlorophenyl) -2-(1H-imidazol-1-ylmethyl)]-1,3-dioxolan-4-yl}methyl meth-anesulfonate in the presence of sodium hydride furnish the title compounds.     

Synthesis of novel 3-(1,3-thiazol-2-yl)-7,8-dihydroquinoline-2,5(1H,6H)-diones

An efficient method for the synthesis of novel 3-(1,3-thiazol-2-yl)-7,8-dihydroquinoline-2,5(1H,6H)-diones from various 2-dimethylaminomethylidenecyclohexane-1,3-diones, (1,3-thiazol-2-yl)acetonitriles, and dimethylformamide dimethyl acetal was developed. These transformations proceeded through intermediate 2-[2-(4-aryl-1,3-thiazol-2-yl)-2-cyanoethenyl]-3-oxocyclohex-1-en-1-olates. They were isolated as piperidinium salts and used in further heterocyclization reactions with aromatic amines, giving novel 1-aryl-3-(1,3-thiazol-2-yl)-7,8-dihydroquinoline-2,5(1H,6H)-diones. These compounds were also obtained by preparative three-step “one pot” synthesis under controlled microwave irradiation. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 412–417, February, 2008.     

Synthesis and anti-proliferative activity studies of 2-(2-(trifluoromethyl)-6-(substituted)imidazo[1,2-b]pyridazin-3-yl)-N-(substituted)acetamide derivatives

A series of novel imidazo[1,2-b]pyridazin-3-yl acetamide derivatives (9a-9j) were synthesized from a 3,6-dichloropyridazine. We have developed a simple strategy for the synthesis of functionally diverse imidazole, and pyridiazine derivatives were reported via a series of steps. The work involves bicyclic imidazo-pyridazine ring formation, halogenation, cynation, hydrolysis, peptide coupling, and Buchwald reaction. The structure of the synthesized compounds was confirmed by IR, ¹H NMR, ¹³C NMR,¹⁹F NMR, mass spectra, and elemental analysis, and purity is checked by HPLC. All synthesized compounds were screened for anticancer activity against A-549 and Du-145 cancer cell lines by MTT assay. The preliminary bioassay suggests that most of the compounds show anti-proliferation with different degrees; doxorubicin was used as positive control. The synthesized compound shows IC₅₀ values in the range of 1.74μM to 16.17μM in both cell lines. The compounds 9e , 9g , and 9h were active compared with doxorubicin in both the cell lines. The compounds having cyclopentyl ring are active compared with higher and lower carbon analogues.     

Synthesis of S,S-dialkyl-N-(9,10-dioxo-9,10-dihydroanthracen-1-yl)sulfoximides and specificities of their base-catalyzed intramolecular heterocyclizations into naphtho[1,2,3-cd]-indol-6(2H)-ones

Heating of 6H-anthra[1,9-cd][1,2]oxazol-6-ones with dialkyl sulfoxides in sulfolane gave S,S-dialkyl-N-(9,10-dioxo-9,10-dihydroanthracen-1-yl)sulfoximides which underwent cyclization to naphtho-[1,2,3-cd]indol-6(2H)-one derivatives on heating in boiling tetrahydrofuran in the presence of sodium methoxide. p-Toluenesulfinic acid was isolated as by-product in the cyclization of S-methyl-S-(4-methylphenyl)-N-(9,10-dioxo-9,10-dihydroanthracen-1-yl)sulfoximide. The heterocyclizations of S,S-dipropyl- and S,S-dibutyl-N-(9,10-dioxo-9,10-dihydroanthracen-1-yl)sulfoximides to 1-ethyl- and 1-propylnaphtho[1,2,3-cd]-indol-6(2H)-ones were accompanied by formation of the corresponding 1-[1-hydroxyethyl(propyl)]naphtho-[1,2,3-cd]indol-6(2H)-ones.