Synthesis and pharmacological investigation of novel 4-(2-methylphenyl)-1-substituted-4H-[1,2,4]triazolo[4,3-a]quinazolin-5-ones as new class of H1-antihistaminic agents

DFT Calculation, Hirshfeld Analysis and X-Ray Crystal Structure of Some Synthesized N-alkylated(S-alkylated)-[1,2,4]triazolo[1,5-a]quinazolines

The present work aimed to synthesize 2-methylthio-triazoloquinazoline derivatives and study their X-ray, NMR, DFT and Hirshfeld characteristics. The cyclocondensation of dimethyl-N-cyanodithiocarbonate with 2-hydrazinobenzoic acid hydrochloride resulted in an intermediate, 2-methylthio-[1,2,4]triazolo[1,5-a]quinazolin-5-one (A), which upon treatment with phosphorus pentasulfide, transformed into the 2-methylthio-[1,2,4]triazolo[1,5-a]quinazolin-5-thione (B). Reaction of 2-methylthio-triazoloquinazolines (A&B) with alkyl halides (allyl bromide and ethyl iodide) in basic medium afforded 4-allyl-2-methylthio-[1,2,4]triazolo[1,5-a]quinazolin-5-one (1; N-alkylated) and 5-ethylthio-2-methylthio-[1,2,4]triazolo[1,5-a]quinazoline (2; S-alkylated), respectively. Their molecular and supramolecular structures were presented. Unambiguously, the molecular structures of 1 and 2 were confirmed via NMR and single-crystal X-ray diffraction. The resulting findings confirmed the structures of 1 and 2 and determined their crystalized system (monoclinic system; P21/n space group). Hirshfeld analysis of 1 revealed the importance of the significantly short O···H (6.7%), S···S (1.2%) and C···C (2.8%); however, the short H···H (42.6%), S···H (16.3%) and C···C (4.3%) were showed in 2 by intermolecular interactions in the molecular packing. The 1,2,4-triazoloquinzolines (1&2) were anticipated to be relatively polar compounds with net dipole moments of 2.9284 and 4.2127 Debye, respectively. The molecular electrostatic potential, atomic charge distribution maps and reactivity descriptors for 1 and 2 were also determined. The calculated nuclear magnetic resonance spectra of the targets 1 and 2 were well correlated with the experimental data.

An overview of triazoloquinazolines: Pharmacological significance and recent developments

Nitrogen heterocyclic rings have participated to constitute most of the drugs and several pharmacologically related compounds. The existence of such hetero atoms/groups in heterocyclic systems privileged specificities in their biological objectives. Particularly, quinazoline and triazole are biologically imperative platforms known to be linked with various pharmacological activities. Some of the prominent pharmacological responses ascribed to these systems are analgesic, antiinflammatory, anticonvulsant, hypnotic, antihistaminic, antihypertensive, anticancer, antimicrobial, antitubercular, antiviral and antimalarial activities. This diversity in the pharmacological outputs for both triazole and quinazoline systems has encouraged the medicinal chemistry researchers to create several chemical routes aiming at the incorporation of two rings in one molecule named triazoloquinazoline system. This system has shown multiple potential activities against numerous targets. Correlation the specific structural features of triazoloquinazoline system with its pharmacological purposes has successively been achieved by performing several pharmacological examinations and structure-activity relationship studies. The development of triazoloquinazoline derivatives and the understanding of their pharmacological targets offer opportunities for novel therapeutics. This review mainly emphases on the medicinal chemistry aspects of triazoloquinazolines including synthesis, reactivity, biological activity and structure activity relationship studies (SARs). Moreover, this review collates literature reported by researchers on triazoquinazolines and provides detailed attention on their analogs pharmacological activities in the perspective of drug development and discovery.

Benzimidazole-Based Quinazolines: In Vitro Evaluation, Quantitative Structure-Activity Relationship, and Molecular Modeling as Aurora Kinase Inhibitors

A series of benzimidazole-based quinazoline derivatives with different substitutions of primary and secondary amines at the C2 position (1-12) were evaluated for their Aurora kinase inhibitory activities. All compounds except for 3 and 6 showed good activity against Aurora kinase inhibitors, with IC50 values in the range of 0.035-0.532 μM. The ligand efficiency (LE) of the compounds with Aurora A kinase was also determined. The structure-activity relationship and the quantitative structure-activity relationship revealed that the Aurora inhibitory activities of these derivatives primarily depend on the different substitutions of the amine present at the C2 position of the quinazoline core. Molecular docking studies in the active binding site also provided theoretical support for the experimental biological data acquired. The current study identifies a novel class of Aurora kinase inhibitors, which can further be used for the treatment of cancer.

Synthesis and antidepressant activities of 4-(substituted-phenyl)tetrazolo[1,5-a]quinazolin-5(4H)-ones and their derivatives

A series of novel 4-(substituted-phenyl) tetrazolo[1,5-a]quinazolin-5(4H)-ones (6a-x) and their derivatives with tetrazole and other heterocyclic substituents (7-14) were designed, synthesized, and evaluated for antidepressant activities in mice. Pharmacological tests showed that three compounds (6l, 6u, and 6v) at a dose of 50 mg/kg significantly reduced the immobility time in the forced swimming test. The most active compound was 4-(p-tolyl)tetrazolo[1,5-a]quinazolin-5(4H)-one (6v), which decreased the immobility time by 82.69 % at 50 mg/kg. Moreover, 6v did not affect spontaneous activity in the open-field test, and this effect was comparable to the antidepressant effect of fluoxetine. Noradrenaline (NE) and 5-hydroxytryptamine (5-HT) levels in the brains of mice in the test sample groups significantly increased at a dose of 50 mg/kg compared with that in the control group. The monoamine oxidase (MAO) level of all test groups was reduced, but this result was not significantly different between the groups. Therefore, we can infer that their underlying mechanisms may involve the regulation of brain monoamine neurotransmitter homeostasis, based on the detected content of NE, 5-HT, and MAO in mouse brain tissue.

Synthesis and β-glucuronidase inhibitory activity of 2-arylquinazolin-4(3H)-ones

2-Arylquinazolin-4(3H)-ones 1-25 were synthesized by reacting anthranilamide with various benzaldehydes using CuCl2·2H2O as a catalyst in ethanol under reflux. Synthetic 2-arylquinazolin-4(3H)-ones 1-25 were evaluated for their β-glucuronidase inhibitory potential. A trend of inhibition IC50 against the enzyme in the range of 0.6-198.2μM, was observed and compared with the standard d-saccharic acid 1,4-lactone (IC50=45.75±2.16μM). Compounds 13, 19, 4, 12, 14, 22, 23, 25, 15, 8, 17, 11, 21, 1, 3, 18, 9, 2, and 24 with the IC50 values within the range of 0.6-44.0μM, indicated that the compounds have superior activity than the standard. The compounds showed no cytotoxic effects against PC-3 cells. A structure-activity relationship is established.

Dichloridobis[3-meth-oxy-methyl-4-phenyl-5-(2-pyrid-yl)-4H-1,2,4-triazole-κN,N]chromium(III) chloride

In the title complex, [CrCl(2)(C(15)H(14)N(4)O)(2)]Cl, the Cr(III) atom is located on a twofold rotation axis and is coordinated by two N,N'-bidentate triazole derivatives and two chloride ions in a distorted octa-hedral CrN(2)N'(2)Cl(2) geometry. One of the two independent Cl(-) counter-anions sits on a special position (site symmetry [Formula: see text].) and is fully occupied, whereas the other is disordered around a twofold rotation axis over two positions in a 2:3 ratio.

Bis(2-hy-droxy-benzoato-κO)bis-[3-(4-meth-oxy-phen-yl)-4-(4-methyl-phen-yl)-5-(2-pyrid-yl)-4H-1,2,4-triazole-κN,N]copper(II) dihydrate

In the title complex, [Cu(C(7)H(5)O(3))(2)(C(21)H(18)N(4)O)(2)]·2H(2)O, the Cu(II) atom is located on a centre of inversion and exists in a tetra-gonally distorted octahedral geometry with a CuN(4)O(2) chromophore. The intra-molecular O-H⋯O hydrogen bond is highly strained due to the mol-ecular geometry and, as a result, is much shorter than expected. Inter-molecular C-H⋯O and C-H⋯O inter-actions are also observed.

Synthesis, antimicrobial evaluation, and docking studies of novel 4-substituted quinazoline derivatives as DNA-gyrase inhibitors

Quinazoline derivatives are reported to have anti-inflammatory, analgesic, antibacterial, and anticancer activities. The incorporation of "OCH₂CONH₂" (oxymethylcarbamide) at 4th position of the quinazoline ring was found to influence the biological activities of the molecules. With this rationale, some new oxadiazolyl methyloxy quinazolines, pyrazolyl acetoxy methyl quinazolines, triazolylmethyloxy quinazolines were synthesized from anthranilic acid through quinazolyl oxyacetylhydrazide intermediates. All the compounds were characterized by IR, ¹H-NMR, EI-MS, and C, H, N analyses and evaluated for their antimicrobial activity. Docking studies on the DNA-gyrase enzyme (1KZN) show their role in the antimicrobial activity of the molecules and explain the higher potency of compounds 6a, 6b, 8a, 8b based on ReRanking scores and binding poses of the molecules.

Synthesis of 2-oxo/thioxooctahydroquinazolin-5-one derivatives and their evaluation as anticancer agents

An environment friendly method for the synthesis of 2-oxo/thioxooctahydroquinazolin-5-one derivatives has been devised using Ceric ammonium nitrate (CAN) as catalyst and polyethylene glycol (PEG) as solvent. The cytotoxic effect of these compounds was studied on U87 human glioma cells, compounds 4c, 4d and 4e are found to exhibit excellent activity at a concentration as low as 0.06 µg/ml.

N′-(4-Methoxybenzoyl)pyridine-2-carbohydrazide

The crystal structure of the title compound, C₁₄H₁₃N₃O₃, exhibits two inter­molecular N—H⋯O hydrogen bonds.