An alternate approach for the synthesis of 2‐substituted‐arylimidazo[4,5‐b]pyridines and their anti‐bacterial activity

An alternate method for the convenient preparation of the imidazo[4,5‐b]pyridines from 2,3‐pyridinediamine and 2‐aryl‐3(1)‐benzoxazine‐4H‐one has been illustrated. The mechanistic pathway for the formation of the product 4 has been proposed. All the compounds prepared herein were screened for their anti‐ bacterial properties.     

Tin Chemistry.Fundamentals,Frontiers, and Applications. Edited by Alwyn G. Davies,Marcel Gielen,Keith H. Pannell and Edward R. T. Tiekink.

John Wiley & Sons, Chichester 2008. 752 pp., hardcover € 199.00.—ISBN 978‐0470517710

     

Syntheses of acyclic C‐glycosidic derivatives of 1,2,4‐triazoles by cycloadditions of 1‐aza‐2‐azoniaallene salts to D‐glucononitrile‐2,3,4,5,6‐pentaacetate

Reported are preparations of acyclic derivatives of 1,2,4‐triazole‐5‐glycosidies 9 by cycloadditions of 1‐aza‐2‐azonia‐allene salts 3 to the nitrile group of D‐glucononitrile‐2,3,4,5,6‐pentaacetate 5 affording triazolium salts 8 , which with aqueous sodium hydogencarbonate are hydrolyzed to 9 . Deacetylation of compounds 9 produced the C‐glycosides 10 .     

Synthesis of α‐[5‐(5‐amino‐1,3,4‐thiadiazol‐2‐yl)‐2‐imidazolylthio]acetic acids

The paper describes synthesis and antituberculosis activity of α‐[5‐(5‐amino‐1,3,4‐thiadiazol‐2‐yl)‐imidazol‐2‐ylthio]acetic acids ( 5a,b ). The compounds were tested against Mycobacterium tuberculosis strain H37Rv in comparison to rifampicin. Compounds exhibited low activity (MIC ≤ 6.25 μg/ml, % inhibition ≥ 24).     

Convenient syntheses of perdeuterated ionic liquids

Facile, gram‐scale, one‐pot or two‐step syntheses for two different types of perdeuterated room‐temperature ionic liquids from commercially available starting materials are described.     

Asymmetric alkylation of N‐acylisoindolin‐1‐ones via α‐bromoimides: A novel route to 1‐substituted isoindolines

Key intermediate in the synthesis of the title compounds 9a‐c and 10a‐c was the chiral α‐bromoimide 1 which has been prepared by radical bromination of the corresponding N‐acylisoindolin‐1‐one 13. 1 was alkylated with silyl enol ethers under Lewis acid catalysis using α‐amidoalkylation methodology. N,N‐diacyliminium ion 14 is presumably the intermediate in this reaction. Further transformations of the alkylated compounds yielded 1‐substituted isoindolines as target compounds.     

Syntheses,electrochemical studies and crystal structures of new unsymmetrical tetrathiafulvalene carboxylate derivatives

A series of new unsymmetrical tetrathiafulvalene carboxylate derivatives ( 7‐11 ) were synthesized and characterized by NMR, MS, electrochemical studies and X‐ray crystal structural determination. Compound 8 showed obvious changes in redox peak potentials as the concentration of p‐toluenesulfonic acid changes.     

A facile three‐components,one‐pot synthesis of pyrimido[4,5‐d]pyrimidine‐2,5‐dione derivatives under microwave‐assisted conditions

Pyrimido[4,5‐d]pyrimidine‐2,5‐dione derivatives have been synthesized in high yields in a novel, onepot, and efficient process by condensation of 6‐amino‐3‐methyl‐2‐(methylthio)pyrimidin‐4(3H)‐one, aldehydes and urea under microwave‐assisted conditions.     

Synthesis of a novel class of 3‐(2′‐benzothiazolyl)‐2,3‐dihydroquinazolin‐4(1H)‐ones under solvent‐free and catalyst‐free conditions

A solvent‐ and catalyst‐free one‐pot three‐component condensation reaction approach was developed for the synthesis of a new class of 3‐(2′‐benzothiazolyl)‐2,3‐dihydroquinazolin‐4(1H)‐ones in relatively good yields.     

Mesoporous Nanofibers from Dual Structure‐Directing Agents in AAO: Mesostructural Control and their Catalytic Applications

Control yourself! The mesoporous silica nanofibers (MSNFs) from dual structure‐directing agents were fabricated inside the pores of porous alumina (AAO, see figure) by using vapor phase synthesis. The pore structures could be controlled to form a range of structures from mesocellular foams to cylindrical mesopores with long‐range order by adding cationic cosurfactants.

     

Silicate Cross‐Linked Bio‐Nanocomposite Hydrogels from PEO and Chitosan

The compositions and the multi phase structures of bio‐nanocomposite hydrogels made from silicate cross‐linked PEO and chitosan are related to some of their physical and biological properties. The gels are injectable and self‐healing because the cross‐linking is physical and reversible under deformation. The presence of chitosan aggregates affects the viscoelastic properties and reinforces the hydrogel network. The chitosan adds advantageous properties to the hydrogel such as enhanced cell spreading and adhesion. In vitro biocompatibility data indicate that NIH 3T3 fibroblasts grow and proliferate on the bio‐nanocomposite hydrogel as well as on hydrogel films.