Some Transformations of 3-(2,2-Dimethyltetrahydro-2H-pyran-4-yl-2-thioxo-2,3-dihydro-1H-spiro(benzo[h]quinazoline-5,1'-cycloheptan)-4(6H)-one

Russian Journal of Organic Chemistry - Starting from 3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)-2-thioxo-2,3-dihydro-1H-spiro(benzo[h]quinazoline-5,1'-cycloheptan)-4(6H)-one, a series of...     

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...     

Synthesis and Anticholinesterase Activity of 4-Arylidene-1-[ω-(dialkylamino)alkyl]-2-phenyl-4,5-dihydro-1(H)-imidazole-5-ones

Russian Journal of General Chemistry - A method for the synthesis of 1-dialkylaminoalkyl-2-phenyl-4-arylidene-5-imidazolones from N-benzoyl-α,β-dehydroamino acid dialkylaminoalkylamides...     

Search for rare decay modes of Californium

The results ofmeasurements on the search for the cluster decay of ²⁵²Cfnucleus with the emission ofthe bound state of eight neutrons are presented. The value of an upper limit ofthe partial probabilities for this process is obtained, which contradicts to the results ofthe recently published work, in which the possible existence of octaneutron was declared. Based on the results of our measurements, the estimations for the upper limits ofpartial probabilities for the emission of ²⁰C, ²⁴O, ²⁸Ne, 32Mg, ³⁶Si, ⁴⁰S, ⁴⁰P, and ⁴⁰Si clusters are given. The estimation for the upper limit of the partial probability of ²⁵⁰Cf decay with the emission of the bound state of six neutrons is also obtained.     

The Stevens rearrangement of propargyl-containing ammonium salts

The Stevens rearrangement of ammonium salts with two propargyl group at the ammonium nitrogen results in the formation of amines containing acetylene-acetylene and acetylene-allene fragments.     

Experimental investigation of preset electrostatic fields in a quasi-electrode system

We describe the results of implementation and breadboard investigations of the method for obtaining constant electric fields of a preset form in a quasi-electrode system. We have constructed a prototype (12 cm in diameter and 30 cm in length) with 36 filamentary electrodes fed with potentials from divider systems with azimuthal distribution laws corresponding to cosθ′, cos2θ′, and cos3θ′ laws with the maximal voltages up to ±2.4 kV. As a result, the electric dipole, quadrupole, and sextupole fields are formed. These fields are analyzed for a 2D cross section of the prototype by physical simulation on a specially developed device with conducting paper. The distributions of the families of equipotential curves measured using the bridge circuit are considered and the strengths of the three types of electric fields are calculated. The results indicate the attainment of all predicted fields with preset parameters and a working area of the aperture of ≥84%. Some other favorable features are also outlined and a number of technical recommendations for producing such fields are given.     

Features of reactions of (<Emphasis Type="Italic">E</Emphasis>)-1-(β-aroylvinyl)pyridinium bromides with binucleophiles

Regardless of pH and a solvent nature the reactions of (E)-1-(β-aroylvinyl)pyridinium bromides with hydrazine led to the formation of pyrazole derivatives. The salts reacted with thiourea via intermediate formation of 4-arylpyrimidine-2-thiol to give (Z)-2-[(β-aroylvinyl)sulfanyl]-4-arylpyrimidines. In the case of N,N'-diphenylthiourea the reaction provided 6-aryl-3-aroyl-1-phenylpyridinium bromides. Pyridine hydrobromide liberated in the reaction course has a major influence on the process chemoselectivity.