Indole systematic name

Indole is a heteroaromatic compound consisting of a fused benzene and pyrrole ring, specifically ben2o[ ]pyrrole. The systematic name, IJT-indole (1) distinguishes it from the less stable tautomer 3JT-indole [271-26-1] (2). Iff-Indole [120-72-9] is also more stable than the isomeric ben2o[ ] pyrrole, which is called isoindole, (2H, (3) and IH (4)). A third isomer ben2o[i ]pyrrole is a stable compound called indoli2idine [274-40-8] (5). 

The systematic name of indigo, also known as indigotin, is 2-(l,3-dihydro-3-oxo-2 //-indol-2-ylidcnc)-1,2-dihydro-3//-indol-3-onc or 2,2 -biindolinylidene-3.3 -dionc. C.I. Vat Blue 1. 73000 4H2-H9-3. It exists as blue-violet needles or prisms with a pronounced coppery luster. It sublimes above 170 °C as a red-violet vapor that condenses on cooling to form dark violet needles. The melting point is 390-392°C. 

Bicyclic systems. The benzo-fused pyrrole heterocycles 13-15 are analogues of naphthalene with carba-zole 16 having an electronic relationship to phenanthrene. The systematic names show the position of the benzenoid ring but the common names indolizine 13, indole 14, isoindole 15, and carbazole 16 (Figure 1) are still widely used. The benzo derivatives of furan and thiophene are named in a similar manner, but their common names have largely fallen into disuse. For the benzo[7>] systems 17 and 20, the [b is commonly omitted. 

It should be pointed out that currently both trivial and systematic names are commonly used for naming the heterocyclic compounds. For example, an organic chemist will recognize without any difficulty the structures connected to names such as furane, pyrrole, pyrrolidine, pyrazole, imidazole, pyridine, or piperidine, despite the fact that all these names are trivial. On the other hand, the complex heterocycles require more sophisticated approaches in order to avoid ambiguity and correctly translate the chemical strucmre into the name. For these, compound names are often made using either trivial name (e.g., indazole for benzopyrazole, benzimidazole, indole, and isoindole) or the Hantzsch-Widman nomenclature, for example, 1,2,3- or 1,2,5-oxadiazoles, 1,3-dioxolane, 1,2- or 1,3-dithiolane, and 1,3- or 1,4-dioxane. It should be noted that the Hantzsch-Widman nomenclature treats the unsaturated heterocycle with maximum number of conjugated double bonds as parent compound. This adds another layer of complexity, giving rise to names such as... 

Many names in common use for heteropolycycles provide little or no information about structure. Most such names were introduced long before any serious attempts were made to systematize nomenclature, and although more systematic equivalents can now be coined in many cases (for example, indole can be named benz[f)]azole or 1-azacyclopentabenzene), it is likely that the use of a substantial residue of trivial names will continue. However, one would not expect many new trivial names to be introduced in the future, except in the natural product area (see Section 1.02.4). 

This year, following a consultation exercise involving members of the Editorial Board, and partly in the interest of getting the Volume published as soon as possible after the end of the year being reviewed, the Index is less comprehensive than formerly. It now includes only systematic heterocyclic ring system names. Thus, wherever a pyrrole is discussed, that would be indexed under pyrroles wherever pyrido[3,4-i]indoles are mentioned an indexed entry under that name will be found similarly aceanthryleno[l,2-e][l,2,4]triazines , azirines , 2f/-pyran-2-ones , 1,2,4-triazoles etc. etc. are listed. But, subjects like 4-ethyl-5-methylpyrrole , 5-acylazirines , 6-alkyl-2//-pyran-2-ones , 3-alkylamino-l,2,4-triazoles , are not listed as such in the Index. Diels-Alder reaction or Fleck coupling etc., are also not indexed. 

In this review, the trivial names mitosane and mitosene [14] (Fig. 1) will be used to describe various mitomycin structures. For example, mitomycin C is 7-amino-9a-methoxymitosane. It should be noted that the numbering of a mitosane differs from the systematic numbering used in Chemical Abstracts for azirino[2, 3 3,4]pyrrolo[l,2-a]indoles, wherein the aziridine nitrogen is the starting point. 

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