4-(对取代苯基)-2-[2-(取代苯基)呋喃-4-甲酰胺]-1',3',4'-均三唑[1,2-d]-1,3,4-噻二唑类衍生物的合成和生物活性

以1-氨基-5-巯基-2-(对取代苯基)-1,3,4-均三唑和5-取代苯基-2-呋喃甲酰异硫氰酸酯为原料, 合成了10个未见文献报道的含苯环连呋喃的均三唑并噻二唑类衍生物, 通过元素分析, ¹H NMR, IR和MS确定化合物的结构, 初步生物活性测试表明标题化合物具有一定的除草活性.     

1,3,4-Oxadiazole N-Mannich Bases: Synthesis,Antimicrobial, and Anti-Proliferative Activities

The reaction of 5-(3,4-dimethoxyphenyl)-1,3,4-oxadiazole-2(3H)-thione 3 with formaldehyde solution and primary aromatic amines or 1-substituted piperazines, in ethanol at room temperature yielded the corresponding N-Mannich bases 3-arylaminomethyl-5-(3,4-dimethoxyphenyl)-1,3,4-oxadiazole-2(3H)-thiones 4a–l or 3-[(4-substituted piperazin-1-yl)methyl]-5-(3,4-dimethoxyphenyl)-1,3,4-oxadiazole-2(3H)-thiones 5a–d, respectively. The in vitro inhibitory activity of compounds 4a–l and 5a–d was assessed against pathogenic Gram-positive, Gram-negative bacteria, and the yeast-like pathogenic fungus Candida albicans. The piperazinomethyl derivatives 5c and 5d displayed broad-spectrum antibacterial activities the minimal inhibitory concentration (MIC) 0.5–8 μg/mL) and compounds 4j, 4l, 5a, and 5b showed potent activity against the tested Gram-positive bacteria. In addition, the anti-proliferative activity of the compounds was evaluated against prostate cancer (PC3), human colorectal cancer (HCT-116), human hepatocellular carcinoma (HePG-2), human epithelioid carcinoma (HeLa), and human breast cancer (MCF7) cell lines. The optimum anti-proliferative activity was attained by compounds 4l, 5a, 5c, and 5d.     

Synthesis and Antibacterial Studies of Some Novel 2-(Coumarin-3-yl)-5-mercapto-1,3,4-oxadiazoles Containing 2,4,6-Trisubstituted s-Triazine Derivatives

A new series of 2-(coumarin-3-yl)-5-mercapto-1,3,4-oxadiazoles based on various aryl thiourea/ureas incorporating a 1,3,5-s-triazine moiety is reported. The components of this series have been obtained by the reaction of cyanuric chloride (1) with 2-(coumarin-3-yl)-5-mercapto-1,3,4-oxadiazole (2). The prepared 2-{(coumarin-3-yl-1,3,4-oxadiazolyl)-5-thio}-4,6-dichloro-s-triazine (3) was subsequently treated with morpholine (4) to form 2-{(coumarin-3-yl-1,3,4-oxadiazolyl)-5-thio}-4-(morpholino)-6-chloro-s-triazine (5). This was further treated with various substituted aryl urea/thioureas (6a–k/7a–k) to afford the title compounds 8a–k and 9a–k, which were and tested for their antibacterial activity (MIC) against different microorganisms. The structures of the novel synthesized compound have been established on the basis of ¹H NMR and FT-IR data together with elemental analysis.

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.     

Asymmetric synthesis of a 3,4-substituted pyrrolidine by l-proline catalyzed direct enolexo aldolization

The asymmetric synthesis of a 3,4-substituted N-tosyl pyrrolidine has been achieved by using l-proline catalyzed 5-enolexo aldolization with high enantio and diastereoselectivity.     

Synthesis and antioxidant properties of organosulfur and organoselenium compounds derived from 5-substituted-1,3,4-oxadiazole/thiadiazole-2-thiols

Organosulfur and organoselenium compounds were synthesized in good yields through reaction with 5-aryl-1,3,4-oxadiazole/thiadiazole-2-thiols and α-chloromethyl arylselenides or 4-(chloromethyl)-2-methylthiazole/2-(chloromethyl)-5-phenyl-1,3,4-oxadiazole. The obtained compounds were characterized by NMR and mass spectroscopy and screened for in vitro antioxidant activity as reflected by free radical scavenging against 2,2-diphenyl-2-picrylhydrazyl (DPPH) and reduction of molybdenum (VI) to molybdenum (V). The compounds have significant antioxidant properties in both applied methodologies.     

An enantioselective approach to 3-substituted pyrrolidines: Asymmetric synthesis for pyrrolidine core of serotonin norepinephrine reuptake inhibitors (SNRIs)

A novel and efficient synthetic approach to enantiopure 3-substituted pyrrolidine skeleton from readily available (S)-PMB glycidyl ether as a starting material and its application to the asymmetric synthesis of pyrrolidine core 1 of serotonin norepinephrine reuptake inhibitors (SNRIs) 2 and 3 are described. The synthesis utilizes the organocatalyzed asymmetric Michael addition reaction as key step.     

Synthesis,characterization and antioxidant,antibacterial activity Zn2+, Cu2+, Ni2+ and Co2+, complexes of ligand [2-(thiophen-2-yl)-1-(thiophen-2-ylmethyl)-1H-benzo[d]imidazole]

New metal complexes of (Zn(II), Co(II), Ni(II) and Cu(II)) based on the ligand 2-(thiophen-2-yl)-1-(thiophen-2-ylmethyl)-1H-benzo[d]imidazole] were synthesized, whose structures were determined with the different spectroscopic techniques ¹H NMR,¹³C NMR, FT-IR, UV–Visible and by mass spectrometry. The thermal analysis was performed by TG-DTA. The antioxidant activity of the ligand and its complexes was evaluated by DPPH (2,2-diphenyl-1-picrylhydrazyl) method, in comparison with the synthetic antioxidant, ascorbic acid. The results obtained showed that the antioxidant activity of the ligand and its complexes is moderate and that the copper complex has a high activity that exceeds that of ascorbic acid. Antimicrobial activity of the ligand and its metal complexes was studied against two Gram-positive bacteria: Bacillus subtilis ILP1428B, Staphylococcus aureus CIP543154 and two Gram-negative bacteria: Pseudomonas aeruginosa ATCC27653, Escherichia coli CIP5412 (American Type Culture Collection)the activity data show that the metal complexes are more potent than the free ligand.     

Synthesis and reactivity of acyclic and macrocyclic uracils bridged with five-membered heterocycles

Replacement of terminal atoms of Br in 1,3-bis(bromopentyl)-5(6)-substituted uracils with 2-mercapto-5-methyl-1,3,4-thiadiazole, 2,5-dimercapto-1,3,4-thiadiazole, 2-mercaptoimidazole, and 2-mercaptobenzimidazoles resulted in a series of acyclic compounds and isomeric heterocyclophanes. Structures of macrocyclic regioisomers were unambiguously determined by NMR data. One of the regioisomers exhibits a hypochromic effect with respect to model compounds. The acyclic uracils obtained bridged with five-membered heterocycles are alkylated with methyliodide and methyl tosylate, and oxidated with m-CPBA, H₂O₂, and I₂.     

Synthesis,antimicrobial and anti-inflammatory activities of some novel 5-substituted imidazolone analogs

In view of potent antimicrobial and anti-inflammatory activities exhibited by 5-substituted imidazolones, a variety of novel imidazolone analogs 3a-l were synthesized by the condensation of different substituted oxazolones 1 with various aromatic amines 2. All the synthesized compounds were screened for in vitro activities against a panel of Gram-positive and Gram-negative bacteria and the yeast-like pathogenic fungus Candida albicans. Several analogs produced good or moderate activities particularly against the tested Gram-positive bacteria Micrococcus luteus and Gram-negative bacteria Pseudomonas aeruginosa and. Meanwhile, compounds 3b and 3c displayed marked antifungal activity against C. albicans. In addition, the in vivo anti-inflammatory activity of the synthesized compounds was determined using the carrageenin-induced paw oedema method in rats. Two of 5-substituted imidazolone derivatives, 3k and 3d show good anti-inflammatory activity. The structures of all the newly synthesized compounds were elucidated using IR, ¹H NMR and ¹³C NMR.     

Maleic acid derivatives in the synthesis of 3-substituted 3,4-dihydroquinoxalin-2(1H)-ones

A process for preparing 3-substituted 3,4-dihydroquinoxalin-2(1H)-ones is proposed. It is based on the reaction of o-phenylenediamine with amides, di- and mono-esters of maleic acid as well as (E)-3-(5-phenyl-1,3,4-oxadiazol-2-yl)acrylic acid in the presence of N,N′-carbonyl-diimidazole.     

Synthesis of pyrrolidine analogues of solamin

A convergent synthesis of pyrrolidine analogues of solamin, which possessed a pyrrolidine in place of the tetrahydrofuran ring, was presented in a facile route from 2,5-trans-bis(methoxycarbonyl)pyrrolidine. The stereochemistry of pyrrolidine core unit was determined by ¹H NMR spectroscopic analysis.     

Synthesis of 1,2,4,5-Tetrakis(1,2,4-Triazolyl) Benzene and 1,2,4,5-Tetrakis(1,3,4-Oxadiazolyl) Benzene Derivatives

Abstract

A series of 1,2,4,5-tetrakis(1,2,4-triazolyl)benzenes and 1,2,4,5-tetrakis(1,3,4-oxadiazolyl)benzenes was synthesized by nucleophilic addition of sodium salts of 4-phenyl-2,4-dihydro-3H-1,2,4-triazole-3-thiones and 1,3,4-oxadiazole-2(3H)-thiones to 1,2,4,5-tetrakis(bromomethyl)benzene. The structure of the newly synthesized compounds was confirmed by elemental analysis, IR and ¹H and ¹³C NMR spectra.

Supplemental 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 resource: 1H and 13C NMR spectra of products (Figures S1-S24).     

In vitro anticancer activity of binuclear Ru(II) complexes with Schiff bases derived from 5-substituted salicylaldehyde and 2-aminopyridine with notably low IC50 values

The binuclear Ru(II) complexes with Schiff bases derived from 5-chlorosalicyladehyde and 2-aminopyridine and its 5-substituted salicylideneimine homologues were tested in vitro against cervical carcinoma (HeLa), metastatic colorectal adenocarcinoma (SW620), lung adenocarcinoma (A549), breast adenocarcinoma (MCF-7), and human lung fibroblast (WI-38) cell lines. All compounds showed strong antiproliferative activity with extremely low IC₅₀ values. The compounds expressed strong activity against gram-positive bacteria, Staphylococcus aureus and Enterococcus faecalis.     

Synthesis and antioxidant evaluation of some new 2-benzoylamino-5-hetaryl-1,3,4-oxadiazoles

A series of new functionalized 2-benzoylamino-5-hetaryl-1,3,4-oxadiazoles were efficiently synthesized via the reaction of the versatile key intermediates, 2-benzoylamino-5-cyanomethyl-1,3,4-oxadiazole (1) and N-(5-(5-amino-3-phenylamino)-1H-pyrazol-4-yl)-1,3,4-oxadiazol-2-yl)-benzamide (13), with some appropriate electrophilic reagents. The structures of the newly synthesized compounds were established on the basis of elemental analyses, spectral data, and by alternative synthesis wherever possible. The mechanisms of the studied reactions are discussed. Also, we evaluate the antioxidant activity of some representative examples of the newly prepared compounds. Among the synthesized compounds, 2-benzoylamino-5-cyanomethyl-1,3,4-oxadiazole (1) and N-(5-(7-methyl-5-oxo-2-(phenylamino)-4,5-dihydropyrazolo[1,5-a]pyrimidin-3-yl)-1,3,4-oxadiazol-2-yl)benzamide (17) showed excellent antioxidant activity and exhibited high protection against DNA damage induced by the Bleomycin iron complex.     

Synthesis and Antimicrobial Activities of Novel Series of 1-((4-Methyl-2-Substituted Thiazol-5-yl)Methyleneam INO)-2-Substituted Isothiourea Derivatives

A novel series of 1-((4-methyl-2-substituted thiazol-5-yl)methyleneamino)-2-substituted isothiourea derivatives was synthesized by alkylation of (Z/E)-1-((4-methyl-2-substituted thiazol-5-yl)methylene)thiosemicarbazide with alkylhalide in acetone. All the newly synthesized compounds were characterized by spectral (IR, ¹H NMR, ¹³C NMR, and mass spectrometry) methods. The newly synthesized compounds were screened for in vitro antimicrobial activity. Most of the compounds show moderate to excellent antimicrobial activity.

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

芳醛-[5-(3,4,5-三甲氧基苯基)-1,3,4-噻二唑-2-巯基]-乙酰腙衍生物的合成及生物活性研究

采用活性基团拼接法, 以2-巯基-5-(3,4,5-三甲氧基苯基)-1,3,4-噻二唑为原料, 经硫醚化、肼解、腙化反应合成了8个芳醛-[5-(3,4,5-三甲氧基苯基)-1,3,4-噻二唑-2-巯基]-乙酰腙衍生物, 并经过元素分析, IR, ¹H NMR, ¹³C NMR对其结构进行了确认. 初步生物活性测试表明, 部分化合物具有一定的抑菌生物活性.     

Efficiency of alkoxyl radical product formation from 5-substituted 3-alkoxy-4-methylthiazole-2(3H)-thiones

In a comparative study, reactions between 5-(p-methoxyphenyl)-substituted 3-alkoxy-4-methylthiazole-2(3H)-thiones and appropriate mediators (BrCCl₃, Bu₃SnH) provided higher yields of alkoxyl radical products (δ-bromohydrins, cyclic ethers, carbonyl compounds) than respective transformations of 5-phenyl- and 5-methyl-substituted derivatives. The unusual selectivity of applied thiohydroxamates to furnish products of O-alkylation, even upon treatment with soft carbon electrophiles, and the marked propensity of 3-alkoxy-5-(p-methoxyphenyl)-4-methylthiazole-2(3H)-thiones to crystallize, facilitated preparation and purification of the new family of alkoxyl radical precursors in a noteworthy manner.     

Synthesis,antifungal and antibacterial activity of calix[4]arene-based 1,3,4-oxadiazole derivatives

We describe the synthesis of some novel p-tert-butylcalix[4]arene-based (5-aryl-1,3,4-oxadiazol-2-yl)2-chloroethanethioate derivatives ( 4a–e ). These compounds were synthesized by the reaction of tetra-tert-butyl calix[4]arene ( 1 ) with (5-aryl-1,3,4-oxadiazol-2-yl)2-chloroethanethioate ( 3a–e ) in the presence of potassium carbonate as a weak base and dry acetone as the solvent. All the newly synthesized calix[4]arene derivatives were characterized by elemental analysis and various spectroscopic methods such as FT-IR, ¹H NMR,¹³C NMR, DEPT, and ESI-MS. The synthesized compounds were tested in vitro for their antibacterial and antifungal activities against Escherichia coli and Aspergillus fumigates in comparison with enrofloxacin and amphotericin as reference drugs, which are normally used for treating such infections. The synthesized compounds showed different inhibition zones against the tested bacteria and fungi. Compound 4c was found to be most effective against A. fumigates, whereas compound 4e was found to be equally effective against E. coli and A. fumigates.     

Design,Synthesis and Antiparasitic Evaluation of Click Phospholipids

A library of seventeen novel ether phospholipid analogues, containing 5-membered heterocyclic rings (1,2,3-triazolyl, isoxazolyl, 1,3,4-oxadiazolyl and 1,2,4-oxadiazolyl) in the lipid portion were designed and synthesized aiming to identify optimised miltefosine analogues. The compounds were evaluated for their in vitro antiparasitic activity against Leishmania infantum and Leishmania donovani intracellular amastigotes, against Trypanosoma brucei brucei and against different developmental stages of Trypanosoma cruzi. The nature of the substituents of the heterocyclic ring (tail) and the oligomethylene spacer between the head group and the heterocyclic ring was found to affect the activity and toxicity of these compounds leading to a significantly improved understanding of their structure–activity relationships. The early ADMET profile of the new derivatives did not reveal major liabilities for the potent compounds. The 1,2,3-triazole derivative 27 substituted by a decyl tail, an undecyl spacer and a choline head group exhibited broad spectrum antiparasitic activity. It possessed low micromolar activity against the intracellular amastigotes of two L. infantum strains and T. cruzi Y strain epimastigotes, intracellular amastigotes and trypomastigotes, while its cytotoxicity concentration (CC₅₀) against THP-1 macrophages ranged between 50 and 100 μM. Altogether, our work paves the way for the development of improved ether phospholipid derivatives to control neglected tropical diseases.     

Synthesis and debenzoylation products of two perbenzoylated 2-substituted 5-D-galactosyl-1,3,4-oxadiazoles

The synthesis of 2-(p-chlorophenyl)-5-[1′,2′,3′,4′,5′-penta-O-benzoyl-D-galactopentitol-1-yl]-1,3,4-oxadiazole is described. Its debenzoylation gave an equilibrium mixture of the 1,3,4-oxadiazole derivative without protection of the hydroxyl group and the N-benzoyl-D-galactono-1,4-lactonehydrazone. A similar equilibrium was observed by debenzoylation of 2-phenyl-5-[1′,2′,3′,4′,5′-penta-O-benzoyl-D-galactopentitol-1-yl]-1,3,4-oxadiazole. The ¹H, ¹³C nmr and ms spectra of these compounds are presented.