Reactions of heterocyclic cations with nitrogen-containing nucleophiles. 10. Synthesis of 3,5,7-triaryl-1,2-oxazepinium perchlorates by the reaction of 2,4,6-triarylpyrylium salts with nitrones and substituted hydroxylamines

2-Substituted 3,5,7-triaryl-1,2-oxazepinium perchlorates were obtained by the reaction of 2,4,6-triarylpyrylium salts in dimethylformamide with nitrones and N-arylhydroxylamines. The products are the first representatives of seven-membered cations with eight electrons.See [1] for Communication 9.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 457–460, April, 1982.     

Oxidative transformations of peridazines

Reactions of peridazines (1H-1,2-diazaphenalenes) with electron-donor reagents (quinones, potassium ferrocyanide) involve multistage oxidative transformations resulting in products of dimarization and (or) dehydration.     

Spectral and quantum-chemical investigation of <Emphasis Type="Italic">ortho</Emphasis>- and <Emphasis Type="Italic">peri</Emphasis>-hydroxy-substituted mono- and diformyl derivatives of 1,5-naphthalenediol

Spectral and quantum-chemical investigation of ortho- and peri-hydroxy-substituted aldehydes, 1,5-naphthalenediol derivatives, was carried out. An unusual spin-spin coupling through an intramolecular hydrogen bond was discovered in the molecule of 1,5-dihydroxynaphthalene-4,8-dicarbaldehyde. It was shown that this dialdehyde is involved into the ring-chain tautomerism. The position of this equilibrium was examined depending on the temperature and the solvent polarity. The effect of the solvent polarity on the benzoid-quinoid tautomerism in the dihydroxynaphthalene-2,6-dicarbaldehyde was established. By the method of quantum-chemical calculations the relative energy stability and conformational structure of dialdehydes were revealed.     

Structure of 4,8-dihydroxynaphthalene-1,5-dicarbaldehyde by the data of 1H NMR Spectroscopy. Spin-spin coupling through a hydrogen bond

Russian Journal of Organic Chemistry -     

Synthesis and reactions of 2-(dimethylaminomethylidene)-6-methoxynaphto[1,8-<Emphasis Type="Italic">bc</Emphasis>]pyran-3-one

The reaction of 6-methoxynaphthol[1,8-bc]pyran-3-one with dimethylformamide dimethyl acetal gave the corresponding 2-dimethylaminomethylidene derivative which reacted with amines to form new 2-aminomethylidene-6-methoxynaphtho[1,8-bc]pyran-3-ones via replacement of the dimethylamino group. 2-Dimethylaminomethylidene-6-methoxynaphtho[1,8-bc]pyran-3-one also reacted with 2,3-dimethylchromenium perchlorate and 1,2,3,3-tetramethyl-3H-indolium perchlorate to give the corresponding merocyanine dyes. The latter were examined for chemosensor and photochromic properties.