VI. Synthesis of Heterocyclic Analogs of γ-Aminobutyric Acid from 3,5-Dinitrobenzoic Acid

A series of 7-carboxy-3-R-1,5-dinitro-3-azabicyclo[3.3.1]non-6-enes was synthesized by reduction of 3,5-dinitrobenzoic acid with sodium borohydride followed by Mannich reaction with formaldehyde and primary amines. The mechanism of decomposition under electron impact of the 3-azabicyclo[3.3.1]nonane was established. Enthalpies of formation of compounds synthesized were calculated by semiempirical PM3 method.     

Kinetic Effects of Electrolytes in Oxidation of Sodium,Potassium, and Tetrabutylammonium 1-Acetonyl-2,4-dinitrocyclohexa-2,5-dienides with 1,4-Benzoquinone

The kinetics of oxidation of sodium, potassium, and tetrabutylammonium 1-acetonyl-2,4-dinitro- cyclohexa-2,5-dienides with 1,4-benzoquinone in acetonitrile and tetrahydrofuran was studied spectrophotometrically. The reaction is of the first order with respect to the substrate and quinone and of the total second order. In the course of the process, a charge-transfer complex with an absorption maximum at about 716 nm is formed, accelerating the reaction. The rates of its accumulation and consumption increase with increasing concentrations of reactants and decrease on addition of sodium or tetrabutylammonium perchlorate. The factors facilitating association of adducts in solution (increase of the concentration in THF, addition of NaClO₄ or [N(C₄H₉)₄]ClO₄), decelerate oxidation owing to decrease of the negative charge in the cyclohexadienide ring of the contact ion pair of the adduct as compared to the free ion.     

Synthesis and conformation of 6,8,10-trinitro-1,4-dioxaspiro[4.5]decane

cis, trans-6,8,10-Trinitro-1,4-dioxaspiro[4.5]decane was synthesized by reduction of the corresponding spirocyclic anionic δ-complex with potassium tetrahydroborate. The molecular structure and the conformation of the title compound were established by X-ray diffraction analysis and¹H NMR spectroscopy. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1713–1717, September, 1999.     

3-Azabicyclo[3.3.1]nonane Derivatives: IV. Synthesis of Amino Acids with 3-Azabicyclo[3.3.1]nonane Fragment

A series of 1.5-dinitro-3-azabicyclo[3.3.1]non-6-enes was prepared by reduction of 1-R-2,4- and 1-R-3,5-dinitrobenzenes with potassium borohydride followed by Mannich reaction with formaldehyde and amino acids. The molecular structure of (6-bromo-1,5-dinitro-3-azabicyclo[3.3.1]non-6-en-3-yl)acetic acid was studied by X-ray diffraction analysis. The mechanism of decomposition under electron impact was determined for (7-methoxy-1,5-dinitro-3-azabicyclo[3.3.1]non-6-en-3-yl)acetic acid.     

3-Azabicyclo[3.3.1]nonane Derivatives: III. Synthesis of 3-Substituted 9-Acetonyl-1,5-dinitro-3-azabicyclo[3.3.1]-non-6-en-8-ones by Mannich Condensation of the Janovsky σ-Adduct of 2,4-Dinitrophenol with Acetonide Ion

A number of 9-acetonyl-1,5-dinitro-3-azabicyclo[3.3.1]non-6-en-8-one derivatives were synthesized by Mannich condensation of 3-acetonyl-2,4-bis(aci-nitro)cyclohex-5-en-1-one disodium salt with formaldehyde and primary amines.     

Reactions of Aromatic Nitro Compounds: LXXIV. Azo Coupling of Anionic Nitroarene σ-Complexes with Aromatic Diazo Compounds. Effect of Reaction Conditions on the Yield of Nitroazobenzenes

Effect of a number of factors on the yield of nitroazobenzenes in the reaction of 4-nitro- and 4-dimethylaminobenzenediazonium tetrafluoroborates with anionic adducts derived from 1,3-dinitrobenzene was studied. Conditions were found which allow nitroazobenzenes to be prepared in 80-90% yield.     

3-Azabicyclo[3.3.1]nonane Derivatives: VIII. Synthesis and Properties of 6(7)-R-3,3-Dimethyl-1,5- dinitro-3-azoniabicyclo[3.3.1]non-6-ene Iodides

N-Alkylation of 6(7)-R-1,5-dinitro-3-methyl-3-azabicyclo[3.3.1]non-6-enes with methyl iodide afforded a series of quaternary ammonium salts whose yield depended on the solvent polarity and character of substituents located in positions 6 or 7 of substrate. The presence of electron-withdrawing groups reduced the yield of the target products compared to unsubstituted compound, whereas the electron-donor substituents increased the yield. As shown by the X-ray diffractionstudy the congormation of the substances was not changed in the course of quaternization. The DTA-TG analysis revealed that in the first stage of thermolysis the 6(7)-R-3,3-dimethyl-1,5-dinitro-3-azoniabicyclo[3.3.1]non-6-ene iodides suffer dealkylation. Two fragmentation paths of compounds synthesized under electron impact were observed: elimination either of methyl iodide or aziridinium cation.     

3-Azabicyclo[3.3.1]nonane Derivatives: IX. Synthesis and Molecular Structure of 3-Azabicyclo[3.3.1]nonane-1,5-diamines in Solution and in Solid State

During catalytic reduction with hydrogen on nickel of a series of 3-substituted 1,5-dinitro-3-azabicyclo-[3.3.1]non-6-enes alongside nitro groups reduction occurred also hydrogenation of the double bond. New diamines of the 3-azabicyclo[3.3.1]nonane series were synthesized, and their structure was established by means of IR, ¹H and ¹³C NMR spectroscopy and X-ray diffraction study.