V. V. Mezheritskii

Synthesis of peri-annelated heterocyclic systems

Publisher Summary This chapter discusses the synthesis of peri-annealated (peri-condensed) heterocyclic systems. peri-annelated (peri-condensed) heterocyclic systems imply structures 1 (where X is a heteroatom; Y, Z are heteroatoms or a hydrocarbon fragment), which contain a tricyclic nucleus where the heterocycle is linked to two other rings at the contiguous sides. Peri-heterocyclic systems with four to seven-membered heterorings are discussed. Since the chemical nature of a heterocyclic system is determined by the valent state of the heteroatom, the names used for a lot of periheterocycle series cannot be considered to be very suitable. Peri-heterocycles serve as dyes, luminophores, energochromophores, organic conductors, and bioactive compounds. The chapter also discusses synthesis of peri-annelated heterocycles such as peri-heterocycles with four membered heteroring, peri-heterocycles with five membered heteroring and single heteroatom, and peri-heterocycles with five-membered heteroring and two heteroatoms.

Synthesis and rearrangements of 7H-pyrrolo[3,2-e][1,2,4]triazolo[1,5-c]-and 7h-pyrrolo[3,2-e][1,2,4]triazolo[4,3-c]pyrimidines

Abstract7H-Pyrrolo[3,2-e][1,2,4]triazolo[1,5-c]pyrimidines were synthesized by the reactions of 2-ethoxymethyleneamino-1H-pyrrole-3-carbonitriles with acid hydrazides and by the reactions of aminoiminopyrimidines (prepared based on the above-mentioned carbonitriles) with acid chlorides.

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.

Ambident chemosensors based on benzo[h]chromen-2-one

Schiff bases derived from 7-hydroxy-4-methyl-2-oxobenzo[h]chromene-8-carbaldehyde in solution exist as equilibrium mixtures of benzoid and quinoid tautomers. The fraction of the quinoid tautomer increases with rise in solvent polarity. The Schiff base containing a benzo-15-crown-5 fragment on the nitrogen atom was shown to be a new ambident chemosensor capable of selectively binding transition metal cations via reaction at the o-hydroxyaldehyde imine fragment and alkaline-earth metals via host-guest interaction with the crown ether moiety. This compound exhibits a pronounced sensor activity toward Mg2+ and Ba2+ ions and is a selective naked-eye fluorescent chemosensor for Cu2+ and Co2+ ions.

Peri-Annulated Heterocyclic Systems. Part I

Publisher Summary The chapter presents various aspects of the chemistry of peri-fused heterocyclic systems taking into account the new findings. The chapter discusses the previously developed sequence, describing successively the compounds with larger heterocycles, with increasing number of heteroatoms in the heteroatom order N,O,S, and occasionally other heteroatoms. This chapter draws attention to the peri-fused heterocyclic naphthalene derivatives with a four-membered heterocyclic ring. Those peri-annulated heterocycles with a closed π-system that possess a double bond or another π- or p-electron “bridge” situated in the peri-position of the naphthalene ring opposite to the heterocycle should be set apart. A large number of stable representatives of four-membered heterocycles with nitrogen or oxygen ring heteroatom are described, among them also their benzoannulated derivatives. The chapter describes the peri-annulated heterocyclic naphthalene derivatives with a four-membered hetero ring— namely, (1)Naphth[1,8-bc]azete, (2)Naphtho[1,8-bc]phosphate, (3)Naphth[1,8-bc]oxete, (4)Naphtho[1,8-bc]thiete and its S-Oxides (5)Naphtho[1,8-bc]borete and (6)Naphtho[1,8-bc]silete .

Trifluoroacetylation of 3-methyl-1H-1,2-diazaphenalenes of the naphthalene and acenaphthene series

Acylation of 3-methyl-1H-1,2-diazaphenalenes of the naphthalene and acenaphthene series with trifluoroacetic anhydride afforded the corresponding N- and C-trifluoroacetyl derivatives and dimerization products of 3-methyl-6-methoxy-1H-1,2-diazaphenalene.

Structure of peri-hydroxy- and peri-methoxy-substituted aldehydes and ketones according to spectral data and quantum-chemical calculations

The structure of peri-hydroxy- and peri-methoxy-substituted aldehydes and ketones of the naphthalene, acenaphthene, and acenaphthylene series and the nature of intramolecular interactions between the peri- substituents therein were determined by spectral (IR, UV, 1H NMR), X-ray diffraction, and quantum-chemical methods.

peri-Amino ketones of the acenaphthene and acenaphthylene series

Abstractperi-Amino-substituted methyl and aryl ketones of the acenaphthene and acenaphthylene series were subjected to protonation and acylation at the nitrogen atom, dehydrogenation, and reactions with aldehydes. Conformations of substituents in the peri positions and probability for their participation in intra- and intermolecular transformations were determined on the basis of spectral data and quantum-chemical calculations.

Cyclic tautomer of 1,5-diacetyl-4,8-dihydroxynaphthalene and its reaction with hydrazine

Demethylation of 1,5-diacetyl-4,8-dimethoxynaphthalene by the action of anhydrous aluminum chloride gave 6-acetyl-2,5-dihydroxy-2-methylnaphtho[1,8-bc]furan which reacted with hydrazine to produce 3,8-dimethyl-1,2,6,7-tetraazapyrene.

New synthetic approach to peri-hydroxy-substituted carbonyl acenaphthene derivatives

A new approach to the synthesis of peri-hydroxyacenaphthoyl compounds has been developed on the basis of acylation (formylation) of 5-acyloxyacenaphthenes. The reactions are accompanied by formation of the corresponding 3- and 8-acyl-substituted isomers. In some cases, the latter can be isolated and identified by 1H NMR spectroscopy.