Synthesis of 4,4′-Oxydibenzoic Acid Amides and Sulfonamides Containing 2-Arylaminopyrimidine Moieties

Russian Journal of Organic Chemistry - New 4,4′-oxydibenzamides and sulfamoyl derivatives of 4,4′-oxydibenzoic acid containing pharmacophoric 2-arylaminopyrimidine fragments in the...     

Synthesis of substituted [1,2,4]oxadiazino[2,3-a]indole-7,8-dicarbonitriles

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Crystallographic report: The crystal structure of 2‐benzo[b]thienylgermatrane

The germanium atom is penta‐coordinated and adopts trigonal bipyramidal geometry. The 2‐benzo[b]thienyl group and the nitrogen atom each occupy an apical position with the transannular N → Ge bond distance being 2.180(4) Å. Copyright © 2003 John Wiley & Sons, Ltd.     

Synthesis and cytotoxic activity of silacycloalkyl‐substituted heterocyclic aldehydes and their thiosemicarbazones

A series of 5‐[1‐methylsilacyclo‐pentyl/‐hexyl]‐2‐furfural, 5‐[1‐methylsilacyclo‐pentyl/‐hexyl]‐2‐thiophene carbaldehyde and 1,1‐bis(5‐formyl‐2‐furyl)silacyclo‐pentane/‐hexane and their thiosemicarbazones has been synthesized and subjected to antitumour assay. The effects of the substituents and the heterocycle were examined to establish structure–activity relationships. Thiosemicarbazones of 5‐(1‐methylsilacyclohexyl)furfural and 5‐(1‐methylsilacyclopentyl)furfural were very active (1.0–4.0 µg ml^?1) in vitro against human fibrosarcoma HT‐1080 and mouse hepatoma MG‐22A cells. At the same time, they were less toxic for normal fibroblasts 3T3. All compounds synthesized exhibited low or moderate toxicity (LD₅₀ 152–1904 mg kg^?1). Copyright © 2005 John Wiley & Sons, Ltd.     

An unusually stable pyridine-2-selenenyl chloride: structure and reactivity

According to an X-ray diffraction study, pyridine-2-selenenyl chloride (1) characterized by unusually high stability both in solutions and in the solid state adopts a dimeric structure formed by two secondary intermolecular Se···N interactions. However, it slowly transforms into zwitterionic T-shaped pyridinium-2-selenenyl dichloride (2) in a dichloromethane solution. Conformational features, electronic structures, and reactivities of 1 and 2 are discussed on the basis of experimental and theoretical (quantum chemical calculations) data.     

Formation of pyrimidin-2-ylcyanamide and 2-aminopyrimidine in the reaction of aniline derivatives with cyanamide and dimethylamino-1-pyridyl-2-propenone

Substituted o- and p-nitroanilines and m-benzylaminoanilines in the reaction with cyanamide failed to yield the corresponding arylguanidines, and in the presence of 3-dimethylamino-1-(3-pyridyl)-2-propen-1-one formed 4-pyridyl-substituted pyrimidin-2-ylcyanamides and 2-amino-pyrimidines.     

Synthesis, structure, and toxicity of arylgermatranes

A series of tolylgermatranes were synthesized. Their structures and the length of the transannular N→Ge bond were determined. It was shown that arylgermatranes are less toxic than the corresponding silatranes.     

Neutron Time Interferometry

We compare a Mach-Zehnder interferometer in time for cold neutrons with its well-known spatial counterpart and demonstrate the intimate connection between space and time for both setups. Further, we outline a combined space-time interferometer, which coherently splits a wavepacket in longitudinal and lateral direction. On the way towards time interferometry neutron computer holography seems to be an attractive application. It allows the three-dimensional reconstruction of an object from the scattered intensity, but in contrast to holography with light, there is no need for a reference wave. On the other hand, the possible resolution is worse than in the light case.     

Synthesis and1H,13C,and29Si spectroscopic investigation of 2-thienyl(2′-Furyl)- and 2′-thienyl[2′-(4′,5′-dihydrofuryl)]silanes

The complete series of 2-thienyl(2-furyl)- and 2-thienyl[2-(4,5-dihydrofuryl)]silanes have been synthesized, and the influence of the character and number of substituents on the chemical shifts in the¹H,¹³C, and²⁹Si spectra has been investigated.DeceasedTranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1220–1225, September, 1995.     

A Chain Catalytic Reaction Involving Pd Cluster as Chain Carrier

   α−Alkyl- and α,α′-dialkyl-substituted benzylic alcohols PhCR′R′′OH (R′=H, Me, Et, Bu; R′′=H, Me) are transformed to the corresponding dilbenzylic ethers and water in acid-free neat substrate media shortly after the addition of the palladium(I) cluster [Pd₄(CO)₄(OAc)₄] (1). During the catalytic reaction occurring under anaerobic conditions, cluster 1 is gradually decomposed to form Pd black, whereas neither original cluster 1 nor Pd black is responsible for the observed reaction. The true reaction catalyst is generated from cluster 1 after a short induction period. On the basis of the reaction kinetics and the HREM, X-ray diffraction, DTA-TG, and elemental analysis data, the catalytic dehydration is suggested to occur through a nonradical chain mechanism involving an unstable intermediate Pd cluster as the chain carrier.