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Heptacoordinated diphenyllead; hexa- and pentacoordinated triphenyllead and tin compounds derived from 5H-benzimidazo[1,2-c]quinazoline-6-thione are reported. The same molecular structures were found in solution by 119Sn and 207Pb NMR and in the solid state by X-ray diffraction analysis. The ligand was bound through S and N giving a four-membered ring. Due to the tension of the chelate ring in the penta- and hexacoordinated compounds, the nitrogen approaches the metal atom from an oblique direction giving a weak coordination. Hexacoordinated metal atoms were obtained by Lewis bases coordination to the polycyclic tin and lead compounds, which was possible because the M-phenyl groups form a cavity that allows the bases to approach from the opposite direction to the sulfur atom. In some crystals, two molecules formed a cavity where a solvent molecule was included. A heptacoordinated diphenyllead bound to two ligands and having the less common pentagonal bipyramidal geometry and cis-mer configuration with two sulfur atoms lying very close together was obtained.

Cyclocondensation of 2-(1H-benzimidazol-2-yl)anilines 1a,b with carbon disulfide in the presence of potassium f-butoxide in boiling DMF afforded the corresponding benzimidazo[1,2-c]quinazoline-6(5H)-thiones 2a,b. Treatment of these compounds with hydrazine hydrate at reflux in ethanol gave the hydrazine derivatives 3a,b which were subsequently cyclised to the title compounds 4a-f on heating with orthoesters in ethanol.

Novel 5a,10,14b,15-tetraaza-benzo[a]indeno[1,2-c]anthracen-5-one and benzimidazo[1,2-c]quinazoline derivatives were synthesised in good yields in two or three steps from 2-(2-aminophenyl)indole and 2-(2- aminophenyl)benzimidazole. Microwave irradiation in homogeneous phase or in dry media was used in order to improve reactions where conventional heating (metal or oil bath) was limited. (C) 2000 Elsevier Science Ltd.

Metastasis in breast cancer is a leading cause of mortality among women in many countries. This study investigated the anti-cancer role of benzoimidazoquinazoline and benzimidazotriazin; two novel compounds that were designed, synthesized, structurally elucidated, and biologically evaluated as potent anti-angiogenic agents that act through inhibition of vascular endothelial growth factor receptor-2 (VEGFR2). Breast cancer was induced by inoculation of Ehrlich Ascites Carcinoma (EAC) cells. Seventy swiss albino mice were randomly divided into 7 groups, 10 animals each: (1) normal, (2) control EAC group, (3) cisplatin treated group, (4&5) benzoimidazoquinazoline treated (5 mg/kg and 10 mg/kg), (6&7) benzimidazotriazin treated (5 mg/kg and 10 mg/kg). The expression of miR-122 was assessed in the tumor tissue by quantitative PCR, and the VEGF level was determined in serum by ELISA. VEGFR2 and cluster of differentiation (CD)34 were assessed by immunohistochemistry. Serum ALT, AST, creatinine, and urea were measured. Treatment with benzoimidazoquinazoline and benzimidazotriazin decreased tumor weight and serum levels of VEGF, and down-regulated expression of VEGFR2 and CD34 in the tumor tissue. miR-122 was upregulated, particularly in the benzimidazotriazin (10 mg/kg) group. Relative to cisplatin, the novel compounds were less toxic to kidneys. Benzoimidazoquinazoline and benzimidazotriazin are promising anti-cancer agents that act through inhibition of angiogenesis and thus provide a new strategy for advancement of chemotherapy.

A highly efficient, selective, and rapid transformation of primary amines and diamines to isothiocyanates and cyclic thioureas is disclosed. As opposed to established approaches that employ toxic or volatile electrophilic liquids and require reaction control (i.e., slow addition, cooling), this protocol utilizes the bench-stable, solid reagent (Me4N)SCF3 at room temperature. The method is characterized by operational simplicity, high speed, efficiency, high functional group tolerance, and late-stage applicability. The byproducts are solids, allowing isolation of the target compounds by filtration.

New benzimidazo[1,2-c]quinazoline-6(5H)-thiones were prepared by cyclization of 3-(2-aminophenyl)quinazoline-2-thioxo-4-ones. Alkylation of these products led to S-alkyl derivatives of benzimidazo[1,2-c]quinazolines.

The aza-Wittig reaction of iminophosphoranes derived from N-substituted o-azidobenzamides, 2-(o-azidophenyl)-benzimidazole, -benzothiazole or -3,1-benzoxazin-4-one with heterocumulenes leads to functionalized quinazolines.Iminophosphoranes 9, derived from N-substituted o-azidobenzamides, react under mild conditions with isocyanates to form 4H-3,1-benzoxazine-4-imines 11 which are converted into 2-substituted-4(3H)-quinazolinones 12.Iminophosphoranes 9 also react with carbon disulfide and carbon dioxide to give the quinazolinones 13 and 14 respectively.Iminophosphorane 26, derived from 2-(o-azidophenyl)benzimidazole, reacts with isocyanates, carbon disulfide and carbon dioxide to form 6-substituted benzimidazoquinazolines 27, 28, and 29 respectively.In benzene at room temperature, iminophosphorane 31, reacts with isocyanates yielding quinazolinoquinazolines 34.Compounds 34 can also be prepared from iminophosphorane 36 and isocyanates.Iminophosphorane 40 derived from 2-(o-azidophenyl)benzothiazole reacts with aliphatic and aromatic isocyanates or isothiocyanates to give 7H-benzothiazoloquinazoline-7-imines 42.Iminophosphorane 40 also reacts with carbon dioxide or carbon disulfide to afford the corresponding isocyanate 43 or isothiocyanate 44, The molecular structures of 11d and 42a have been determined by X-ray diffraction methods.

The aza-Wittig reaction of iminophosphoranes derived from N-substituted o-azidobenzamides or 2-(o-azido)phenyl benzimidazole with isocyanates, carbon dioxide or carbon disulphide, lead to functionalized 4(3H)-quinazolinones and benzimidazoquinazolines respectively.

A number of benzimidazoquinazolines (5-9) have been synthesized starting from 2-(2'-aminophenyl)benzimidazole (3).Reaction of 2-aminoanthranilide (2) with thiophosgene has been carried out and the mechanism of thiophosgene heterocyclisation has been discussed.The compounds have been tested for their anthelmintic and antinmicrobial activities but none of them shows any noteworthy activity.

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