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Two regioselective methods for the synthesis of nucleosides in the series of 3-phenyl- and 3-ethoxycarbonyl-1,2,4-triazolo[5,1-c][1,2,4]triazin-4-ones were developed. The first route involves a Vorbrüggen glycosylation reaction. The second one is based on condensation of 1,2,4-triazolo[5,1-c][1,2,4]triazin-4-one sodium salts with protected 1-bromo-sugar derivatives. [ABSTRACT FROM AUTHOR]

A convenient synthesis of a series of pyrazole, pyridine, pyridinethione, pyridazine, pyrazolo[3,4-b]pyridine, imidazo[1,2-a]pyrimidine, and pyrazolo[5,1-c][1, 2, 4]triazine derivatives incorporating a pyrimidine moiety, via the reactions of the versatile, readily accessible 3-oxo-N-(pyrimid-2-yl)butanamide with the appropriate reagents, is described. [ABSTRACT FROM AUTHOR]

Abstract: Pyrrolo[2,1-c][1,4]benzodiazepine-β-glucuronide prodrugs 15a–b, with a potential for selective therapy of solid tumors by PMT and ADEPT have been designed, synthesized and evaluated for selective cytotoxicity in the presence of the enzyme β-glucuronidase. The prodrugs have been found to possess reduced cytotoxicity compared to the parent moieties, and are excellent substrates for the enzyme, exhibiting cytotoxicity selectively in the presence of the enzyme. Enhanced water solubility and improved stability are the other important outcomes upon modifying these molecules as their prodrugs. [Copyright &y& Elsevier]

Abstract: A series of 1,2,3-triazole-containing pyrrolo[2,1-c][1,4]benzodiazepine dimers have been prepared efficiently by employing a ‘click’ chemistry protocol. This method involves 1,3-dipolar cycloaddition of terminal alkynes with organic azides using a Cu(I)-catalyst. Further, these molecules exhibited interesting DNA-binding affinity profiles. [Copyright &y& Elsevier]

Abstract: The synthesis and binding studies of a series of 3-acylpyrazolo[5,1-c][1,2,4]benzotriazine 5-oxides 8-substituted are reported. High-affinity ligands at benzodiazepine site on GABAA receptor complex (GABAA/BzR complex) were obtained when the 3-aroyl substituent is represented by a five-member heteroaroyl ring (furoyl-, thenoyl-, and pyrroyl-). Moreover the type of heteroaroyl ring at position 3 influences the feature of the substituent at position 8 to obtain high-affinity ligands: a ‘hydrogen-bond acceptor ring’ at position 3 is synergic with an electron donor substituent at position 8, while a ‘hydrogen-bond donor ring’ is synergic with a withdrawing substituent. Compounds 8a, 9b, and 11 were deeply studied in vivo for their pharmacological effects considering six potential benzodiazepine actions: motor coordination, anticonvulsant action, spontaneous motor activity and explorative activity, anxiolytic-like effects, mouse learning and memory modulation, and ethanol-potentiating action. To rationalize and qualitatively interpret the GABAA/Bz binding affinities of compounds 8a and 11, a dynamic molecular modeling study has been performed, with the aim of assessing the preferred geometry of protein–ligand complex. [Copyright &y& Elsevier]

Abstract: A new class of C8-linked pyrrolo[2,1-c][1,4]benzodiazepine–chalcone conjugates have been prepared by employing a solid-phase synthetic protocol. In this strategy an intramolecular aza-Wittig reductive cyclization approach has been utilized. Interestingly, some of these molecules have shown enhanced DNA-binding affinity and promising anticancer activity on a large number of human cancer cell lines. [Copyright &y& Elsevier]

Abstract: A new synthetic pathway has been developed for the preparation of imine-containing pyrrolo[2,1-c][1,4]benzodiazepines (PBDs) and their dimers. Selective reduction of aromatic azides as well as aliphatic amides in a single step leading to an intramolecular reductive cyclization process by employing LiAlH4 or LiBH4 provides the cyclized imines. [Copyright &y& Elsevier]

Abstract: 1,2,3-Triazole based molecules are useful pharmacophores for several DNA-alkylating and cross-linking agents. A series of A/C8, C/C2 and A/C8-C/C2-linked 1,2,3-triazole–PBD conjugates have been synthesized by employing ‘click’ chemistry. These molecules have exhibited promising DNA-binding affinity and anticancer activity in selected human cancer cell lines. [Copyright &y& Elsevier]

Abstract: Alkylation of 1H-6-methyl-3-phenyl-pyrazolo[5,1-c][1,2,4]triazole and 1H-7-ethoxycarbonyl-6-methyl-3-phenyl-pyrazolo[5,1-c][1,2,4]triazole using different alkylating agents leads regioselectively to 1-N-alkylated products. The hydrolysis–decarboxylation of 1,6-dimethyl-7-ethoxycarbonyl-pyrazolo[5,1-c][1,2,4]triazole yields a compound identical with that obtained by the direct methylation of 1H-6-methyl-3-phenyl-pyrazolo[5,1-c][1,2,4]triazole. The 1-N-alkylation is confirmed by NMR spectroscopy and mass spectrometry. [Copyright &y& Elsevier]

Abstract: A facile method for the solid-phase synthesis of pyrrolo[2,1-c][1,4]benzodiazepine dimers has been developed. p-Nitrophenyl carbonate Wang resin attached to 2-amino-5-methoxy-methyl benzoate has been utilized as the resin-bound starting material and these reactions are monitored by FT-IR spectroscopy of resin beads. [Copyright &y& Elsevier]

Abstract: An efficient method for the reduction of aromatic azides in both solution and solid-phase has been developed by employing BF3·OEt2/EtSH. This report also describes resin cleavage employing this reagent system. Further, this protocol has been utilized for the solution as well as the solid-phase synthesis of pyrrolo[2,1-c][1,4]benzodiazepines, including the naturally occurring antibiotic DC-81 and fused [2,1-b]quinazolinones. [Copyright &y& Elsevier]

Abstract: 1-Arylimidazolidine-2-thiones (1a–g) were synthesized by the condensation reaction of N-arylethylenediamines with carbon disulfide in xylene medium. Their further alkylation with methyl iodide led to the formation of some biologically active 1-aryl-2-methylthio-imidazolines (2a–g). The 7-(4-methylphenyl)-3-methylthio-5H-6,7-dihydroimidazo[2,1-c][1,2,4]triazole (4b) was obtained by the alkylation of the respective 7-(4-methylphenyl)-2,5,6,7-tetrahydroimidazo[2,1-c][1,2,4]triazol-3(H)-thione (3b) with methyl iodide. Antimicrobial activities of 1-aryl-2-methylthio-imidazolines (2a–g) and the 7-(4-methylphenyl)-3- methylthio-5H-6,7-dihydroimidazo[2,1-c][1,2,4]triazole (4b) are presented. All tested compounds showed MIC in the range of 11.0–89.2μM. Compounds 2a,e were found to be equipotent to chloramphenicol in vitro, whereas 2a,c,e–g and 4b showed superior activity (MIC) to ampicillin. [Copyright &y& Elsevier]

Abstract: The synthesis and the binding study of new 3-arylesters and 3-heteroarylpyrazolo[5,1-c][1,2,4]benzotriazine 5-oxide 8-substituted are reported. The nature of these substituents (in terms of lipophilic and electronic features) seems to influence the binding affinity. High-affinity ligands were studied in mice in vivo for their pharmacological effects, considering six potential benzodiazepine actions: anxiolytic-like effects, muscle relaxant effects, motor coordination, anticonvulsant action, spontaneous motor activity, and ethanol-potentiating action. Compounds 4d and 6d showed an inverse-agonist profile. These compounds were evaluated also for their binding at benzodiazepine site on GABAA receptor complex (GABAA/BzR complex) subtype to evaluate their subtype selectivity. [Copyright &y& Elsevier]

Abstract: The design, synthesis and evaluation of four novel pyrrolo[2,1-c][1,4]benzodiazepine (PBD) prodrugs (1a,b and 2a,b; ) for potential use in carboxypeptidase G2 (CPG2)-based antibody-directed enzyme prodrug therapy (ADEPT) is reported. Although all four prodrugs were shown to be less cytotoxic than the released parent PBDs 3 and 4, the urea prodrugs 1b and 2b were found to be too unstable for use in ADEPT, whereas carbamates 1a and 2a are both stable in an aqueous environment and are good substrates for CPG2. [Copyright &y& Elsevier]

A new method is proposed for obtaining 3,4-polymethylene-1,2,4-benzothiadiazine 1,1-dioxides by reacting o-halobenzenesulfonamides with lactim ethers. Attempts were undertaken to synthesize quaternary salts of the heterocycles obtained. [ABSTRACT FROM AUTHOR]

The article discusses the nucleophilic rearrangement of annelated azines involving the atoms of a side chain. It mentions that the structure of the compounds was proved by using X-ray analysis and the reaction of the product of aminomethylation with hydrazine hydrate gave the pyrazolyl derivative rather than tricyclic diazepine. It says that identification of the intermediate in the reaction occurs thru ANCORC mechanism.

Agents which can recognize and bind specific sequences of DNA offer selective therapy through the modulation of specific transcription factors or genes. Recently, there has been renewed interest in the field of anticancer minor groove binders. This may be attributed to the fact that many compounds of this class have demonstrated significant antitumor activity against a wide variety of cancers in recent clinical trials. This review will discuss the recent efforts to overcome the drawbacks of existing minor groove binding anticancer agents through rational drug design based on scaffolds with known antitumor activity., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)