D. E. Dmitriev

Synthesis of secondary and tertiary aminofurazans

Reactions of nitrofurazans with primary and secondary amines were studied. Conditions were found which allow the efficient replacement of the nitro group with these nucleophiles. Transformations of the amidoxime fragment, which is bound to the furazan ring and contains an amino substituent, enable one to substantially expand the spectrum of polyfunctional derivatives. The structures of the amines synthesized were studied by X-ray diffraction analysis.

1H, 13C, and 14N NMR study of 3-methylfurazans with nitrogen-containing substituents at position 4

Abstract3-Methylfurazans with nitrogen-containing substituents at position 4 were studied by 1H, 13C, and 14N NMR spectroscopy. A correlation between the chemical shifts in 13C NMR spectra of these furazans and monosubstituted benzenes with the same substituents was found. The increments for a number of furazan-containing substituents were determined for the first time.

Synthesis of 3-alkyl-4-aminofurazans

A “one-pot” method for the synthesis of 3-alkyl-4-aminofurazans from ethyl β-alkyl-β-oxopropionates was developed. The multistep process involves hydrolysis of the ester, nitrosation at the activated methylene group, and treatment of the resulting intermediate with an alkaline solution of hydroxylamine in the presence of urea.

Electrocatalytic transformation of malononitrile and cycloalkylidenemalononitriles into spirobicyclic and spirotricyclic compounds containing 1,1,2,2-tetracyanocyclopropane fragment

Electrolysis of malononitrile and cycloalkylidenemalononitriles in EtOH in an undivided cell in the presence of NaBr affords spirobicyclic compounds containing a 1,1,2,2-tetracyanocyclopropane fragment in 50—88% yields.

NMR spectroscopic study of 3-nitrofurazans

Abstract3-Nitrofurazans with different substituents at position 4 were studied by 1H, 13C, and 14N NMR spectroscopy. A correlation between chemical shifts (CS) in the 13C NMR spectra of furazans and benzene with similar substituents was revealed. Increments for a series of new substituents were determined. The 13C and 14N CS values presented can be used as a reliable set of reference data.

(Pyrrol-1-yl)furazans

Short-time reactions of 3-amino-4-R-furazans with 2,5-dimethoxytetrahydrofuran in boiling acetic acid afford (pyrrol-1-yl)furazans. One of the products was characterized by X-ray diffraction analysis.

1,5-Diazabicyclo[3.1.0]hexanes and 1,6-diazabicyclo[4.1.0]heptanes: a new method for the synthesis, quantum-chemical calculations, and X-ray diffraction study

A new method was developed for the synthesis of 6-substituted 1,5-diazabicyclo[3.1.0]hexanes and 7-substituted 1,6-diazabicyclo[4.1.0]heptanes by condensation of N-monohalotrimethylene- and N-monohalotetramethylenediamines with carbonyl compounds in the presence of bases. X-ray diffraction studies and quantum-chemical B3LYP/6-31G* calculations demonstrated that the conformations of the resulting bicyclic systems are stabilized by stereoelectronic interactions. As a result, a boat conformation prevails in 1,5-diazabicyclo[3.1.0]hexanes, whereas the energies of chair, half-chair, and boat conformations of 1,6-diazabicyclo[4.1.0]heptanes are equalized.

Reaction of 3-(4-Chlorofurazanyl-3-N(O)N-azoxy)-4-nitrofurazan with Weak Bases

When 3-(4-chlorofurazanyl-3-N(O)N-azoxy)-4-nitrofurazan reacts with weak bases and nucleophiles, we observe selective attack on the carbon atom bonded to the nitro group; we do not observe products formed by substitution of the chlorine.

Reactions of cyanofurazans with β-dicarbonyl compounds

In the presence of nickel acetylacetonate, β-dicarbonyl compounds readily add at the nitrile group of 4-R-3-cyanofurazans to form enaminofurazans. The adducts obtained from 4-amino-3-cyanofurazan underwent intramolecular cyclization on heating with AcOH in EtOH to give furazano[3,4-b]pyridine derivatives in high yields.

Synthesis of 2-(furazanyl)indolizines

Heating ofN-[2-(4-methylfurazan-3-yl)-2-oxoethyl]-2-methylpyridinium bromides inN,N-dimethylaniline affords indolizine derivatives, whereas in aniline a mixture of indole and indolizine derivatives is formed.