Series Of N-aryl Research Articles

Fluorination of α-diazo-γ-lactams with the Olah reagent

A series of N-aryl α-fluoro-γ-lactams were successfully prepared by hydrofluorination of diazo counterparts with the Olah reagent in moderate yields. This approach was also applied to bromofluorination with N-bromosuccinimide as electrophilic bromine source.

Synthesis of N-Aryl- and N-alkyl-Substituted Imidazolium Silver Complexes: Cytotoxic Screening by Using Human Cell Lines Modelling Acute Myeloid Leukaemia.

A series of N-aryl- and N-alkyl substituted imidazoles has been synthesised and complexed with Ag+ to obtain silver-NHC complexes of the form [Ag(NHC)2 ]X. These silver-NHC complexes were tested in vitro against the human cell lines HL-60 and MOLM-13, which both model acute myeloid leukaemia (AML). A substantial difference in cytotoxicity was revealed varying in the range 13-4 μM and 22-9 μM for HL-60 and MOLM-13, respectively. Furthermore, this study revealed that when an alkyl group is installed on the imidazole scaffold, its position substantially influences the cytotoxicity of the corresponding silver NHC complex.

Sterically hindered N-aryl/benzyl substituted piperidoimidazolin-2-ylidene palladium complexes and their catalytic activities

A series of N-aryl (2a,b) or benzyl (2c,d) substituted piperidoimidazolinium salts and their palladium complexes (3a-d) were prepared and characterized by 1H, 13C NMR, IR spectroscopy and elemental analysis. The crystal structures of 3a and 3c have been determined by X-ray crystallography. Thermogravimetric analysis (TGA) was applied to complexes (3a–d). The palladium complexes have been employed as catalyst for Suzuki-Miyaura cross coupling. The N-aryl substituted complex 3b was a highly efficient precatalyst and successfully employed in Suzuki-Miyaura cross coupling reactions of (hetero)aryl chlorides with arylboronic acids in air. In addition, the oxidative addition step of the reaction mechanism involving chlorobenzene and the catalysts 3a, 3b, 3c and 3d were computationally investigated by the DFT-ω-B97X-D method and complete agreement were obtained with the catalytic results. To measure σ-donating and π-acceptor properties of the new ligands, the rhodium carbonyl complexes were also prepared.

New series of N-aryl- and N-heteroaryl-d-glucuronamides as potential anticancer agents: synthesis and spectroscopic analysis

A series of structurally diverse d-glucuronic acid derivatives, comprising various aromatic scaffolds, was prepared and characterized with the aim of developing new prodrug candidates. The presented ultrasound-assisted protocol provides a convenient way for the synthesis of N-aryl- and N-heteroaryl-substituted d-glucuronamides with improved bioavailability. New conjugates containing benzene, naphthalene, indole, quinoxaline, and benzothiazole moieties were prepared in high yields (41–85%). Their structures were elucidated by various spectroscopic methods, including NMR, and their potential in the photoactivation of molecular oxygen was monitored by EPR spectroscopy. The application of the presented approach for the synthesis of potentially biologically active compounds makes the method attractive because of their potential use in biomedical and pharmaceutical chemistry.

Synthesis, antimalarial and antitubercular activities of meridianin derivatives

Meridianins are marine-derived indole alkaloids, known to possess kinase inhibitory and antimalarial activities. A series of N-aryl and heteroaryl sulfonamide derivatives of meridianins were prepared and screened for antimalarial activity against D6 and W2 strains of Plasmodium falciparum. 2-Nitro-4-trifluoromethyl sulfonamide derivative 14v displayed promising antiplasmodial activity against both strains with IC50 values of 2.56 and 3.41 μM, respectively. These compounds were not cytotoxic to mammalian cell lines including VERO (monkey kidney fibroblasts), LLC-PK1 (pig kidney epithelial cells) and four cancer cell lines; SK-MEL (human malignant, melanoma), KB (human epidermal carcinoma), BT-549 (ductal carcinoma), SK-OV-3 (human ovary carcinoma) up to 25 μg/ml. Furthermore, all sulfonamide derivatives along with acyl, alkyl and C-ring modified derivatives of meridianins were screened for antitubercular activity against a sensitive strain (H37Rv) of Mycobacterium tuberculosis (Mtb), wherein several compounds showed MIC values in the range of 5.2–304.8 μM. Meridianin C (3) and meridianin G (7) showed anti-tubercular activity with MIC values of 111.1 and 304.8 μM, respectively. The C-ring modified analog 12 exhibited potent anti-tubercular activity against H37Rv strain of Mtb with MIC of 5.2 μM. Furthermore, the most potent analogs 11b and 12 were screened against two clinical isolates of M. tuberculosis INHR and MDR and one laboratory generated mutant strain RifR. These two analogs 11b and 12 displayed promising activity against these resistant strains with MIC values in the range of 5.2–187.7 μM. This is the first report on the anti-tubercular activity of this scaffold.

Green Synthesis of Alkane Bridged Bisimidazolium Salts Under Solvent-Free Conditions

A series of N-aryl or N-methyl substituted bisimidazolium dichloride or dibromide salts with different alkyl bridge lengths (n = 1–4) have been synthesized starting from N-arylimidazoles or N-methylimidazoles with dialkyl bromides or the less expensive but less reactive dialkyl chlorides under solvent-free conditions. This green protocol provided most bisimidazolium chloride and bromide salts in good yields, and the reaction time was shortened to a few hours. In two examples, we showed either bisimidazolium dichloride (1a) or dibromide salt (3c) can be easily converted to the corresponding dihexafluorophosphate salt (1a′ or 3c′) in near quantitative yield.

N-aryl pyrazoles: DFT calculations of CH acidity and deprotonative metallation using a combination of lithium and zinc amides

A series of N-aryl and N-heteroaryl pyrazoles have been deproto-metallated using a 2,2,6,6-tetramethylpiperidino-based mixed lithium-zinc combination. Mono-, di-, and tri-iodides have been obtained after subsequent trapping with iodine, depending on the substrate and on the quantity of base used. The results have been discussed in the light of the CH acidities of the substrates, determined both in the gas phase and in THF solution using the DFT B3LYP method.

Synthesis and hypolipidemic activity of N-substituted phthalimides. Part V

A series of N-aryl- or N-(1,2,4-triazol-yl)-phthalimides ( 4a– 4i) have been synthesized starting from phthalic anhydride ( 1) and an appropriate amine ( 2a– 2i). All compounds presented hypolipidemic activity, but compound 4d proved to be the most active and reduced plasma cholesterol and triglyceride levels in Swiss white mice significantly.

Synthesis and Antiviral Activity of N-Acyl Derivatives of 4,6-Di-( tert -butyl)-2-aminophenol

In recent years, the results of a number of experimental and clinical investigations have shown that antioxidants are promising candidates in the group of drugs used for the treatment of viral pathologies. The inhibiting action of antioxidants with respect to viral replication was reported for herpes simplex virus (HSV), hepatitis C, Epstein – Barr virus, cytomegalic inclusion virus, etc. [1]. It was also demonstrated that phenolic antioxidants of plant origin reduce HIV expression in tests on cell cultures [2]. In this context, we have undertaken the search for viral inhibitors among aminophenol derivatives known to be capable of controlling the generation and utilization of free radicals [3]. Previously [4], we described the synthesis of N-acyl-substituted 4,6-di-tert-butyl-2-aminophenols and reported on the results of pharmacological tests revealing sufficiently high anti-HSV activity in some of the synthesized compounds. In continuation of this search for new antiviral agents in the class of spatially constrained o-aminophenol, we have synthesized a series of N-aryl and N-cycloalkyl derivatives of 4,6-di-tert-butyl-2-aminophenol and tested these compounds for antiviral activity with respect to HSV and influenza species in cell cultures. The target compounds (I – VI) were synthesized by treating 3,5-di-tert-butylpyrocatechol with aniline, its derivatives, and cyclohexylamine in petroleum ether or methanol.

Studies on the Mass Spectra of N‐Aryl α,β‐Unsaturated γ‐Lactams

AbstractThe mass spectra of a series of N‐aryl α,β‐unsaturated γ‐lactams were studied. Besides the molecular ion, the three characteristic fragments such as [M+‐29], [M+‐55], and [M+‐82] were commonly found in a series of N‐Aryl α,β‐unsaturated γ‐lactams in EI/MS. Further more the mechanism for the interpretation of these fragments is also de scribed.

Electrochemical oxidation of 2-phenyl-1,2-benzisothiazol-3(2H)-ones and related compounds in acetonitrile. A study using microelectrodes

Abstract The electrochemical oxidation of 2-phenyl-1,2-benzisothiazol-3(2H)-ones and related compounds was studied by conventional and microelectrode techniques. Hammett plots were drawn for a series of N-aryl substituted 2-phenyl-1,2-benzisothiazol-3-(2H)-ones and compared with those of the selenium analogues, 2-phenyl-1,2-benzisoselenazol-3(2H)-ones. Controlled potential electrolysis furnished the corresponding sulphoxides and the reaction pathway was shown to proceed through an ECE mechanism.

Additions and Corrections - Buspirone Analogues. 1. Structure-Activity Relationships in a Series of N-Aryl- and Heteroarylpiperazine Derivatives.

Additions and Corrections - Buspirone Analogues. 1. Structure-Activity Relationships in a Series of N-Aryl- and Heteroarylpiperazine Derivatives.

Buspirone analogs. 1. Structure-activity relationships in a series of N-aryl- and heteroarylpiperazine derivatives

A series of analogues of buspirone was synthesized in which modifications were made in the aryl moiety, alkylene chain length, and cyclic imide portion of the molecule. These compounds were tested in vitro for their binding affinities to rat brain membrane sites labeled by either the dopamine antagonist [3H]spiperone or the alpha 1-adrenergic antagonist [3H]WB-4101. Compounds were also tested in vivo for tranquilizing properties and induction of catalepsy. Potency at the [3H]spiperone binding site was affected by alkylene chain length and imide portion composition. Nonortho substituents on the aryl moiety had little effect on [3H]spiperone binding affinity. Structure-activity relationships of ortho substituents demonstrated only modest correlations between the receptor binding data and physical parameters of the substituents. The complex nature of the drug-receptor interactions may be understood in terms of the fit of buspirone to a hypothetical model of the dopamine receptor.

Studies of quinoline derivatives

1. Condensation of secondary arylamines with paraldehyde gives a series of N-aryl substituted quinolines, 2. Eight quaternary N-arylquinolinium salts have been prepared and described, in which the N-aryl radical is phenyl, 0-tolyl, p-tolyl,α-napththyl, andβ-naphthyl.