Reactions of phenothiazine thiocyanate derivatives with dialkyldithiophosphoric acids

The addition products of dialkyldithiophosphoric acids to the CN bond in 3-thiocyanatophenothiazine rearrange to give relatively more stable S-(3-phenothiazinyl)-N-dialkoxythiophosphoryldithiocarbamates. An analogous derivative, formed in the reaction of diethyldithiophosphoric acid with 3-thiocyanato-10-ethylphenothiazine, is unstable and decomposes to give 3-mercapto-10-ethylphenothiazine and diethylisothiocyanatothiophosphate. The main pathway in the reaction of dialkyldithiophosphoric acids with 10-(thiocyanatoacetyl)phenothiazine appears to be acid-catalyzed cyclization of the latter to give 4-(10-phenothiazinyl)-3-thiazolin-2-one. However, the formation of 3-dialkoxythiophosphoryl-4-thiazolidinone-2-thiones is also observed in these reactions; these products result from rearrangement of the addition products of dithio acids to CN bonds, followed by subsequent heterocyclization via elimination of phenothiazine. The molecular structure of 3-diisopropoxythiophosphoryl-4-thiazolidinone-2-thione was investigated by x-ray structural analysis; the heterocyclic fragment in this molecule exists in an envelope conformation with the nitrogen atom deviating from the plane of the other four atoms.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 460–467, February, 1991.     

Reactions of 5,7-Dichloro-4,6-dinitrobenzofuroxane and -furazane with Triphenylphosphine

Reactions of 5,7-dichloro-4,6-dinitrobenzofuroxane and 5,7-dichloro-4,6-dinitrobenzofurazane with triphenylphosphine proceed through a nucleophilic aromatic substitution of chlorine and nitro groups in the sixmembered ring of the heterocycles. The structure of the phosphorylation products was established from the IR, ³¹P NMR, and mass spectra and from XRD and elemental analysis. Schemes of the routes of the phosphorylation are discussed.     

Experimental and theoretical study on 6-substituted pyridoxine derivatives. Synthesis of cyclic 2,4,5,6-tetrakis-(hydroxymethyl)pyridin-3-ol acetonides

Synthetic approaches to three cyclic 2,4,5,6-tetrakis(hydroxymethyl)pyridin-3-ol acetonides were developed. Among seven possible mono- and diketals, six-membered cyclic ketal incorporating the hydroxymethyl group in the 4-position turned out to be the most thermodynamically favorable. The experimental data were consistent with the results of quantum-chemical calculations of the Gibbs energies of formation of different acetonides. The structure of the isolated compounds was studied by X-ray diffraction.     

Structure of the product of interaction of N-vinylcaprolactam with 3-chlorophenylisocyanate

The [2+2]-cycloaddition reaction of N-vinylcaprolactam with 3-chlorophenylcyanate yielding 1-(3-chlorophenyl)-4-[1H-perhydroazepinone-2]-azetidinone-2 is studied. The structure of the obtained compound is determined by single crystal XRD.     

1,10‐Diaza‐18‐crown‐ether,Modified by Phosphonate Pendant Arms – Synthesis,Structure, and Picrate Extraction Properties

Reaction of O,O′‐diisopropyl‐3‐methyl‐1,2‐butadienylphosphonate with 1,10‐diaza‐18‐crown‐6 in the presence of a catalytic amount of iPrONa leads to the new crown‐ether derivative, containing phosphonate pendant arms ( L ). The structure of the compound obtained was investigated by single crystal X‐ray diffraction analysis, IR, ¹H and ³¹P{¹H} NMR spectroscopy, and microanalysis. In the crystal structure the side arms of L are in an anti disposition relative to the macrocyclic cavity. It was established that phosphorylation of 1,10‐diaza‐18‐crown‐6 by allenylphosphonate results in an increase of extraction of NaPic and KPic, whereas LiPic and NH₄Pic are extracted practically in the same level.     

The status of the Super-FRS at FAIR

The Super-FRS will be a large-acceptance two-stage superconducting fragment separator with three exit branches serving different experimental areas. Due to the high primary-beam intensity of up to 10¹² ions/s a challenging design of the target area and the components used in the first dipole Super-FRS is necessary. These efforts include high-power production targets, beam-dumps to catch the remaining primary beam, and radiation resistant magnets. In this contribution we summarize the recent developments on these issues.     

Reaction of 1,7,7-trimethylbicyclo[2.2.1]heptane-2,3-dione with hexaethyltriamidophosphite in the presence of diethylammonium chloride. Synthesis and the three-dimensional structure of (1,7,7-trimethyl-2-oxobicyclo[2.2.1]hept-3-yloxy)tris(diethylamino)phosphonium chloride

The reaction of 1,7,7-trimethylbicyclo[2.2.1]heptane-2,3-dione with hexaethyltriamido-phosphite in the presence of diethylammonium chloride afforded a stable quasiphosphonium salt, viz., (1,7,7-trimethyl-2-oxobicyclo[2.2.1]hept-3-yloxy)tris(diethylamino)phosphonium chloride, as one diastereomer (racemate, 1R*,3S*,4S*). Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 383–385, February, 2006.     

Competition of the Hantzsch and boese reactions in the interaction of 1-thiocarbamoylthiosemicarbazide and phenylchloropyruvic acid methyl ester

1-Thiocarbamoylthiosemicarbazide, the synthetic equivalent of thiourea and thiosemicarbazide, reacts with phenylchoropyruvic acid methyl ester exclusively as thiourea (Hantzsch reaction) forming 2-hydrazo-4-methoxycarbonyl-5-phenylthiazole. Diacetylation and reductive fission of this hydrazo compound was carried out, and also oxidation to the corresponding azo compound, readily accomplished with using dimethyl sulfoxide.A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center, Russian Academy of Sciences, Kazan 420088; Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1554–1560, November, 1999.