7-Halogenated 7-Deaza-2′-deoxyinosines

The synthesis of the 7-deaza-2′-deoxyinosine derivatives 3a – c with chloro, bromo, and iodo substituents at position 7 is described. Glycosylation of the 7-halogenated 6-chloro-7-deazapurines 4a – c or of the 7-halogenated 6-chloro-7-deaza-2-(methylthio)purines 9a – c with 2-deoxy-3,5-di-O-(4-toluoyl)-α-D -erythro-pentofuranosyl chloride ( 5 ) furnished the intermediates 7a – c and 11a – c , respectively, which gave, upon deprotection, the desired nucleosides 3a – c .     

Efficient synthesis of 5-substituted 2-aryl-6-cyanoindolizines via nucleophilic substitution reactions

2-Aryl-6-cyano-7-methyl-5-indolizinones were successfully converted into 2-aryl-5-chloro-6-cyano-7-methylindolizines. The obtained 5-chloroindolizines readily underwent nucleophilic substitution at position 5 leading in high yields to novel 5-functionalised indolizines.     

Formation of Hollow Polymeric Microspheres with Functionalized Surface on the Basis of Latex Particles with Multilayered Structure

Summary: Latices with “core-shell” particle morphology containing polar “core” and a shell on the basis of copolymer of styrene and functional vinyl monomer (allyl alcohol, vinyl acetate, methacrylic acid) has been obtained as a result of graft-copolymerization initiated from the surface of (meth)acrylate latex particles previously modified with functional polyperoxides. The processes of functional shell grafting as well as the processes of latex particle swelling with obtaining hollow microspheres due to neutralization of core carboxylic groups have been studied.     

7-Substituted 7-Deaza-2′-deoxyguanosines: Regioselective Halogenation of Pyrrolo[2,3-d]pyrimidine Nucleosides

The synthesis of 7-chloro-, 7-bromo-, and 7-iodo-substituted 7-deaza-2′-deoxyguanosine derivatives 2b – d is described. The regioselective 7-halogenation with N-halogenosuccinimides was accomplished using 7-[2-deoxy-3,5-O-di(2-methylpropanoyl)-β-D -erythro- pentofuranosyl]-2-(formylamino)-4-methoxy-7H-pyrrolo[2,3-d]- pyrimidine ( 4 ) as the common precursor. A one-pot reaction (2N aq. NaOH) of the halogenated intermediates 5a – c furnished the desired compounds. Also the 7-hexynyl derivative 2e of 7-deaza-2′-deoxyguanosine is described.     

Parallel solution-phase synthesis of substituted 2-(1,2,4-triazol-3-yl)benzimidazoles

A solution-phase synthesis for the preparation of substituted 2-(1,2,4-triazol-3-yl)benzimidazoles from triazole aldehydes and ortho-phenylenediamines has been developed for the purpose of producing diverse lead generation libraries. Crude products were obtained and further purified by mass-guided preparative HPLC.     

Phytochemical Characterization,Antioxidant Activity,and Cytotoxicity of Methanolic Leaf Extract of Chlorophytum Comosum (Green Type) (Thunb.) Jacq

Chlorophytum genus has been extensively studied due to its diverse biological activities. We evaluated the methanolic extract of leaves of Chlorophytum comosum (Green type) (Thunb.) Jacques, the species that is less studied compared to C. borivilianum. The aim was to identify phytoconstituents of the methanolic extract of leaves of C. comosum and biological properties of its different fractions. Water fraction was analyzed with matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Nineteen compounds belonging to different chemical classes were identified in the methanolic extract of leaves of C. comosum (Green type) (Thunb.) Jacques. In addition to several fatty acids, isoprenoid and steroid compounds were found among the most abundant constituents. One of the identified compounds, 4′-methylphenyl-1C-sulfonyl-β-d-galactoside, was not detected earlier in Chlorophytum extracts. The water fraction was toxic to HeLa cells but not to Vero cells. Our data demonstrate that methanolic extract of leaves of C. comosum can be a valuable source of bioactive constituents. The water fraction of the extract exhibited promising antitumor potential based on a high ratio of HeLa vs. Vero cytotoxicity.     

Intramolecular cyclization of ω‐haloalkylsubstituted thiophosphorylacetonitriles: Synthesis and stereochemistry of 3‐cyano‐2‐oxo‐1,2‐thiaphosphacyclanes

Intramolecular S‐alkylation in a series of ω‐haloalkyl‐substituted thiophosphorylacetonitriles 5–7 presents an effective synthetic route to the hitherto unknown 3‐cyano‐2‐oxo‐1,2‐thiaphospholanes 14 and thiaphosphinanes 15 . The compounds were obtained as a mixture of cis‐ and trans‐isomers that were resolved to individual stereoisomers in most cases. For some of them, X‐ray diffraction analysis has been performed. It was shown that ³¹P NMR spectroscopy can be used to assign the stereochemistry of 3‐cyano‐2‐oxo‐1,2‐thiaphosphacyclanes. © 2002 John Wiley & Sons, Inc. Heteroatom Chem 13:1–21, 2002; DOI 10.1002/hc.1101