Of peri-annellated heterocyclic systems

The construction of peri-annelated heterocyclic systems I-XXIII is carried out by the addition of a three carbon-atom fragment to the ben-zoheterocycle (3 — 2) or of a heterocycle to a naphthalene nucleus (4 — 2) (see Scheme 1). In practice, the second approach (4 — 2) is used more often. 1,8-Disubstituted naphthalene derivatives serve as the initial compounds, and they may be divided into three main types (5-7) as potential precursors of peri-heterocycles I-XXIII (Scheme 2). 

The nomenclature of peri-naphthalene heterocycles does not follow a common principle. In many original papers, the names of heterocyclic systems are derived from the corresponding peri-annelated hydrocarbon derivatives (1,2-diazaacenaphthylene, 1-oxaphenalene, etc.), from monoheterocycles with an indication of linked positions (naphtho[l,8-6c]furan, naphtho[l,8-de]azepine, etc.), and from benzoannelated heterocycles (benzo[o/]indole, benzo[heterocyclic systems and some compounds have trivial names, for instance, perimidine, naph-thostyryl, and naphtholactone. Moreover, it is necessary to remember some peculiarities in the electronic structure of peri-annelated heterocycles, namely the absence of independent existance of the 7r-closed-loop monoheterocycles which could be a fragment of peri-annelated heterocyclic systems. Therefore, the separation of a heterocycle from the united 7r-system is impossible. In this case, the simplest structure and the tt-electron unit is the whole peri-heterocyclic nucleus. 

Mezheritskii, V. V., Tkachenko, V. V., Synthesis of Peri-Annelated Heterocyclic Systems, 51, 1. 

The subject of this review is a systematization of synthetic methods for constructing a skeleton of a peri-heterocyclic nucleus (with closed-loop and nonclosed-loop 7r-systems) from precusors that do not contain such a nucleus. Conversions of peri-annelated heterocyclic rings and recycli-... 

Naphthalene derivatives in which positions 1 and 8 are linked by one heteroatom are the simplest representatives of the peri-annelated heterocyclic systems. Compounds in this group are interesting because of possi-... 

Peri-annelated heterocyclic systems 411 with the inverse heteroatom orientation are formed on heating anthraquinone-1 -carboxylic acid 410 in aqueous solution of hydroxylamine hydrochloride (64MI1). 

Known compounds in this class include mainly 1,3-oxazine, 1,3-thiazine, 1,3-diazine (perimidine), and to a lesser extent 1,3-dithiine and 1,3-dioxine peri-annelated derivatives. The general strategy for constructing such systems is based on heterocyclization of 8-hydroxy-, 8-mercapto-, or 8-amino-substituted 1-naphthylamines 426 (X = NR)... 

Synthesis of tricyclic compounds containing a 4- to 7-membered heterocycle peri-annelated to a naphthalene system 90AHC(51)1. 

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