Nitrogen‐Rich Compounds of the Lanthanoids: The 5,5′‐Azobis[1H‐tetrazol‐1‐ides] of some Yttric Earths (Tb,Dy, Ho,Er, Tm,Yb, and Lu)

A set of N‐rich salts, 3 – 9 , of the heavy lanthanoids (terbium, 3 ; dysprosium, 4 ; holmium 5 ; erbium, 6 ; thulium, 7 ; ytterbium, 8 ; lutetium, 9 ) based on the energetic 5,5′‐azobis[1H‐tetrazole] (H₂ZT) was synthesized and characterized by elemental analysis, vibrational (IR and Raman) spectroscopy, and X‐ray structure determination. The synthesis of the lanthanoid salts 3 – 9 was performed by crystallization from concentrated aqueous solutions of disodium 5,5′‐azobis[1H‐tetrazol‐1‐ide] dihydrate (Na₂ZT?2 H₂O; 1 ) and the respective Ln(NO₃)₃?5 H₂O and yielded large rhombic crystals of the type [Ln(H₂O)₈]₂(ZT)₃?6 H₂O in ca. 70% of the theoretical yield. The compounds 3 – 9 are isostructural (triclinic space group P ) to the previously published yttrium salt 2 ; they show, however, a clear lanthanoid contraction of several crystallographic parameters, e.g., the cell volume or the Ln? O bond lengths of the Ln³⁺ ions and the coordinating H₂O molecules. The lanthanoid contraction influences the strengths of the H‐bonds, which can be observed as a red shift by 4 cm^?1 in the characteristic IR band, in particular from 3595 cm^?1 ( 3 ) to 3599 cm^?1 ( 9 ). In good agreement with previous works, 2 – 9 are purely salt‐like compounds without a coordinative bond between the tetrazolide anion and the Ln³⁺ cation.     

Synthesis and crystal structure of 4-acetoxy-5,6-dihydro-5,5-dinitro-2H-1,3-oxazineN-oxide

A novel heterocyclic compound, 4-acetoxy-5,6-dihydro-5,5-dinitro-2H-1,3-oxazineN-oxide, has been synthesized by the reaction of the dipotassium salt of 1,1,5,5-tetranitro-3-oxapentane with aqueous acetic acid. The synthesized compound has been studied by X-ray diffraction analysis.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2207–2210, December, 1994.We would like to thank G. V. Lagodzinskaya (Institute of Chemical Physics in Chernogolovka, Russian Academy of Sciences) for recording and interpreting¹H NMR spectra, A. M. Korolev (Institute of Chemical Physics in Chernogolovka, Russian Academy of Sciences) for helpful discussion, and V. I. Fetisov (Institute of Physiologically Active Compounds, Russian Academy of Sciences) for performing quantum-chemical calculations by the AM1 SCF MO LCAO method.     

[2+2]-Photocycloaddition von Cyclohexen an 2-Acetyl-5,5-dimethyl-1,3-cyclohexandion und 3-Acetyl-1,5,5-trimethyl-2,4-pyrrolidindion

Summary Irradiation of solutions of excess cyclohexene and 2-acetyl-5,5-dimethyl-1,3-cyclohexanedione (1), and 3-acetyl-1,5,5-trimethyl-2,4-pyrrolidinedione (4) results mainly in the formation of 1,5-diones2 and5. These originate from intermediate cycloadducts of cyclohexene and theexo-enols of the cyclic 1,3-diketones. The yields decrease with increasing polarity of the solvent. In solution2 and5 are in equilibrium with the cyclic hemiacetales3 and6.

     

Oxidation of 2,6-di-tert-butylphenol with polymer anchored molybdenyl and vanadyl complexes

The oxidation of 2,6-di-tert-butylphenol with tert-butylhydroperoxide (Bu^tO₂H) has been studied using polymer (XAD₄) anchored salicylaldoxime, 1,3-propylene-bis-salicylaldimine and o-phenylene-bis-salicylaldimine complexes of molybdenum and vanadium in acetonitrile. The predominant products formed in the oxidation reactions were 2,6-di-tert-butylbenzoquinone (BQ) and 3,3′-5,5′-tetra-tert-butyldiphenoquinone (dPQ), whereas with some only 2,6-di-tert-butylbenzoquinone was formed. This is the first reported use of polymer anchored molybdenyl and vanadyl complexes in selective oxidation of 2,6-di-tert-butylphenol. Solvent plays an important role in this reaction. The effects of varying the ligand, metal and the support on the catalytic activity in the oxidation of 2,6-di-tert-butylphenol have been studied. With polymer anchored MoO₂(salpen), 81% of 2,6-di-tert-butylbenzoquinone was formed from 2,6-di-tert-butylphenol.     

The Mannich reaction in the synthesis of N,S-containing heterocycles. 7. Effective one-pot synthesis of derivatives of spiro[3,5,7,11-tetraazatricyclo-[7.3.1.0<Superscript>2,7</Superscript>]tridec-2-ene-13,4′-piperidine]

5,11-Disubstituted derivatives of 1′-isopropyl-8-thioxospiro[3,5,7,11-tetrazatricyclo[7.3.1.0^2,7]tridec-2-ene-13,4′-piperidine]-1,9-dicar bonitrile was obtained by the interaction of 10-amino-9-aza-3-azonia-7,11-dicyano-3-isopropylspiro[5,5]undeca-7,10-diene-8-thiolate with 2 equiv. of a primary amine and excess of formaldehyde. An anomalous reaction product was obtained with o-toluidine — 7,9-dicyano-1′-isopropyl-3-(2-methylphenyl)-1,2,3,4-tetrahydrospiro[pyrido[1,2-a][1,3,5]triazine-8,4′-piper idinium]-6-thiolate. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, 1709–1713, November, 2007.     

Investigation on the thermal degradation of acrylic polymers with fluorinated side-chains

The thermal degradation of poly-2,2′,3,3′,4,4′,5,5′,6,6′,7,7′,7″-tridecafluoroheptylacrylate and poly-2,2′,3,3′,4,4′,5,5′,6,6′,7,7′-dodecafluoroheptylmethacrylate has been studied in isothermal conditions at 450-750 °C using pyrolysis-gas chromatography. The type and composition of the pyrolysis products give useful information about mechanism of thermal degradation. It was shown that the main thermal degradation process for both polymers is random main-chain scission. The major degradation products for fluorinated polyacrylate are monomer, dimer, saturated diester, trimer, and corresponding methacrylate. The fluorinated polymethacrylate gives monomer as the main product of thermal destruction. As a result of side-chain reaction, the thermal degradation of the fluorinated polyacrylate also produces remarkable amounts of alcohol. On the other hand, the respective alcohol is only a minor component among the pyrolysis products of the fluorinated polymethacrylate. For both polymers, the main nontrivial degradation product coming from the alkyl ester decomposition is the corresponding fluorinated cyclohexane. The formation of the fluorinated cyclohexanes may be accounted for a nucleophilic bimolecular substitution pathway.     

Reaction of benzothiazol-2-one with 4-hydroxy-4-methyl-2-pentynonitrile

Reaction between the title compounds gave the unexpected 3-[5,5-dimethyl-2,5-dihydrofur-4-yl-2-(3-isopropanol-2-propenonitrile)imino]benzothiazol-2-one, as a result of the addition of two cyanoacetylene molecules.Irkutsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Irkutsk 664033. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 4, pp. 1003–1005, April, 1992.     

Reactions of 2,3-Dioxopyrrolo[2,1-<Emphasis Type="Italic">a</Emphasis>]isoquinolines with Active N-Nucleophiles

It is shown that 2,3-dioxopyrrolo[2,1-a]isoquinolines react readily with aliphatic diamines and hydroxyamine with opening of the dioxopyrrole ring and formation of the corresponding bisenaminoketoamides and hydroxamic acids. Reaction with the thiosemicarbazide and hydrazides of aromatic acids proceeds without opening of the pyrrole ring at the ketone carbonyl. Derivatives of hexahydropyridazine are formed when compounds with carboxyethyl groups at position 1 react with hydrazine. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, 1383–1387, September, 2005.     

Unexpected synthesis of 6-amino-2,3-dihydro-4-pyrone-3-spirocyclohexane

The reaction of 2-amino-2-(trichloromethyl)tetrahydro-4-pyrone-5-spirocyclohexane with ethylenediamine afforded 6-amino-2,3-dihydro-4-pyrone-3-spirocyclohexane, whereas 2-amino-5,5-dimethyl-2-(trichloromethyl)tetrahydro-4-pyrone gave 2-(3-hydroxy-2,2-dimethylpropionylmethylene)imidazolidine in low yield.     

The structure of benzoyldimedone from X-ray diffraction analysis

The structure of benzoyldimedone was established by X-ray diffraction analysis. The only tautomer was found. In this tautomer, the enol proton is covalently bound to the oxygen atom that is remote from the phenyl group. The role of steric and electronic factors in stabilization of the enol structure is analyzed. The geometric characteristics of the ring formed through an intramolecular hydrogen bond are discussed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1074–1076, June, 2000.