Chemistry of heterocyclic quinoneimines. 9. Reaction of benzo[a]phenoxazin-9-one with C-nucleophiles

Selective replacement of the hydrogen atom in the 5 position of the aromatic fragment of the substrate by the residue of a C-nucleophile, which is accompanied by rearrangement of the benzoquinoid structure to a naphthoquinoid structure, occurs in the reaction of benzo[a]phenoxazin-9-one with cyanoacetic acid derivatives under conditions of activation of the reagent.See [1] for Communication 8.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 538–541, April, 1988.     

A new approach to the synthesis of lamotrigine and other 3,5-diamino-1,2,4-triazine derivatives

A new in principle method for the synthesis of 6-aryl(hetaryl)-3,5-diamino-1,2,4-triazines by decomposition of pre-synthesized tetrazolo[1,5-b][1,2,4]triazines was developed. The advantages of this method over traditional methods were demonstrated using the synthesis of a modern antiepileptic preparation lamotrigine, as an example.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 713–719, March, 2005.     

Cyclization of N-alkylazinium cations with bifunctional nucleophiles. 25. Oxidation of tetrahydroquinoxalines condensed with six-membered ring heterocycles

Reaction of six-membered ring heterocycle-annulated tetrahydroquinoxalines with potassium permanganate in acetone results in the formation of oxidation products containing a common system of conjugated double bonds.For Communication 24, see Ref. [1].Translated from Khimiya Geterotsklicheskikh Soedinenii, No. 9, pp. 1260–1263, September, 1987.     

Unusual dimerization of 1-ethyl-1,2,4-triazinium salts into 4a,4b,9,10-tetrahydro-1,3,6,8,8a,10a-hexaazaphenanthrenes

1- Ethyl-3-alkylthio-5-phenyl-l,2,4-triazinium tetrafluoroborates were found to undergo an unusual dimerization on treatment with triethylamine in methanol or ethanol solution. A mechanism for the formation of 4a,4b,9,10-tetrahydro-l,3,6,8,8a,l0a-hexaazaphenanthrenes is proposed.     

Chiroptical properties and new derivatives of cyclopalladated 6-ferrocenyl-2,2′-bipyridine. Molecular structure of a tert-butyl isocyanide derivative

Optically active cyclopalladated 6-ferrocenyl-2,2′-bipyridine has been studied by circular dichroism and luminescent spectroscopy; a replacement of the chloride ion at palladium with the rhodanide ion and tert-butyl isocyanide molecule has been carried out; molecular structure of the product in the latter case has been determined by X-ray diffraction analysis.     

S<Stack><Subscript>N</Subscript><Superscript>H</Superscript></Stack> Reaction of lithiated nitronyl nitroxide with quinoline <Emphasis Type="Italic">N</Emphasis>-oxide

The S_N^H reaction of lithiated 4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-oxyl 3-oxide with quinoline N-oxide affords 4,4,5,5-tetramethyl-2-(1-oxidoquinolin-2-yl)-4,5-dihydro-1H-imidazole-1-oxyl 3-oxide.     

One-pot synthesis of 6H-pyrrolo[2,3-e[1,2,4]triazolo[1,5-a]pyrimidines on the basis of σH-adducts of 6-Nitro[1,2,4]triazolo[1,5-a]pyrimidine with carbonyl compounds

Aromatic, heteroaromatic, and aliphatic carbonyl compounds reacted with 6-nitro[1,2,4]triazolo[1,5-a]pyrimidine in the presence of a base to give stable σ^H-adducts at C⁷. Reduction of the nitro group in the latter is accompanied by tandem autoaromatization of the azine ring and intramolecular cyclocondensation with formation of the corresponding 6H-pyrrolo[2,3-e][1,2,4]triazolo[1,5-a]pyrimidines. Original Russian Text ? E.B. Gorbunov, G.L. Rusinov, R.I. Ishmetova, V.N. Charushin, O.N. Chupakhin, 2008, published in Zhurnal Organicheskoi Khimii, 2008, Vol. 44, No. 1, pp. 130–134. Dedicated to Full Member of the Russian Academy of Sciences G.A. Tolstikov on his 75th anniversary