2-Allyloxy/propargyloxypyridines: synthesis,structure, and biological activity

The alkylation (allylation and propargylation) of 3-cyano-6-dialkylamino-2-pyridones containing a d-annulated ring occurs at the oxygen atom. The structures of the starting compounds and their alkylation products were determined by X-ray diffraction. The neurotropic and antimicrobial activity of alkylation products was examined.     

Proton source size measurements in the eA-->e'ppX reaction

Two-proton correlations at small relative momentum q were studied in the eA(3He,4He,C,Fe)-->e(')ppX reaction at E(0)=4.46 GeV using the CLAS detector at Jefferson Lab. The enhancement of the correlation function at small q was found to be in accordance with theoretical expectations. Sizes of the emission region were extracted, and proved to be dependent on A and on the proton momentum. The size of the two-proton emission region for He was measured in eA reactions for the first time.     

Synthesis of New Fused Thieno[3,2-d]pyrimidines Based on Thieno[3,2-d][1,3]oxazine Derivative

Russian Journal of General Chemistry - A method was developed for the synthesis of new fused amines, thieno[3,2-d]pyrimidine derivatives, starting from the corresponding chloride and various...     

Synthesis of Cyclopenta[4',5']pyrido[3',2':4,5]thieno[3,2-<Emphasis Type="Italic">d</Emphasis>]pyrimidine Derivatives. Dimroth Rearrangement of Triazolopyrimidines

Methods of the preparation of 9- (methylsulfanyl)cyclopenta[4',5']pyrido[3',2':4,5]thieno[3,2-d]- pyrimidines and pentacyclic triazolopyrimidines derivatives were developed. The Dimroth rearrangement of these compounds was studied.     

The interaction between polyelectrolyte microgels of <Emphasis Type="Italic">N</Emphasis>-isopropylacrylamide copolymers and aqueous solutions of alcian blue

The temperature influence on the behavior of microgels based on poly-N-isopropylacrylamide (PNIPA) homopolymer, N-isopropylacrylamide copolymers with sodium methacrylate (PNIPA/MANa), sodium styrenesulfonate (PNIPA/SSNa), and sodium vinylsulfonate (PNIPA/VSNa) was studied. The comparative analysis of the temperature-induced collapse of macro- and microgels was conducted. The interaction between alcian blue and PNIPA, PNIPA/SSNa, PNIPA/VSNa, and PNIPA/MANa gels was studied. The research showed that dye sorption leads to the contraction of oppositely charged microgels. The sorption effectiveness depends on the nature of the ionogenic units. The dye sorption by PNIPA/SSNa microgels is more effective than the sorption by the corresponding macrogels. The AB sorption by PNIPA/MANa microgels is less than the sorption by the corresponding macrogels and by the PNIPA/SSNa microgels. The interaction properties are connected to the structure of the crosslinked polymer chains in the microgels.     

Synthesis of New Fused Thiopyridines and Their Reaction with Acetylacetone in the Presence of Mercury(II) Acetate

Russian Journal of General Chemistry - The method of synthesis of fused thiopyridines via S-alkylation of the corresponding pyridine thiones with propargyl bromide has been elaborated. Fused enol...     

Dimroth rearrangement in the row of new pyrano[3,4-c][1,2,4]triazolo[4,3-a][1,5-a]pyridines and synthesis of new heterocyclic systems: Pyranopyrazolo[4,3-e][1,2,4]triazolopyridines

New and effective methods for the synthesis of derivatives of pyrano[3,4-c][1,2,4]triazolo[4,3-a][1,5-a]pyridines were developed. Synthesized new tetracyclic heterocyclic systems containing pyrano[3,4-c]pyridine ring unknown in the literature were obtained for the first time. The rearrangement of Dimroth in the triazolo[4,3-a]pyridine systems for the first time was studied. The possibility of rearrangement of Dimroth in the new heterocyclic system has been investigated.     

Synthesis of New Fused Furo- and Thienopyridines

Russian Journal of General Chemistry - A method was developed for the synthesis of new fused derivatives of pyrano[4,3-b]thieno(furo)-pyridine, namely...     

Search for the Theta+ Pentaquark in the gammad--> DeltanK+ reaction measured with the CLAS spectrometer

For the first time, the reaction gammad-->DeltanK+ has been analyzed in order to search for the exotic pentaquark baryon Theta+(1540). The data were taken at Jefferson Laboratory, using the Hall-B tagged-photon beam of energy between 0.8 and 3.6 GeV and the CEBAF Large Acceptance Spectrometer (CLAS). No statistically significant structures were observed in the nK+ invariant-mass distribution. The upper limit on the gammad-->DeltaTheta+ integrated cross section has been calculated and found to be between 5 and 25 nb, depending on the production model assumed. The upper limit on the differential cross section is also reported.     

Two-nucleon momentum distributions measured in 3He(e,e'pp)n

We have measured the 3He(e,e'pp)n reaction at 2.2 GeV over a wide kinematic range. The kinetic energy distribution for "fast" nucleons (p>250 MeV/c) peaks where two nucleons each have 20% or less, and the third nucleon has most of the transferred energy. These fast pp and pn pairs are back to back with little momentum along the three-momentum transfer, indicating that they are spectators. Calculations by Sargsian and by Laget also indicate that we have measured distorted two-nucleon momentum distributions by striking one nucleon and detecting the spectator correlated pair.