The nomenclature of heterocyclic compounds is a set of naming systems for heterocyclic compounds . Currently, several nomenclature systems have been adopted for these IUPAC substances : the trivial nomenclature of heterocycles, nomenclature Gancha - Widman and replacement nomenclature .
IUPAC recommends the use of the Ganch-Widmann nomenclature and allows the use of certain trivial names. Despite the fact that traditionally trivial names are very popular, their use is very limited, including in the construction of more complex names of derivative compounds.
Trivial Nomenclature
The trivial names of heterocyclic compounds are usually based on the circumstances of the discovery of these substances (source, characteristic properties, etc.). For example, methylpyridines have the trivial name " picolines " (from lat. Picatus - covered with tar), since they were isolated from coal tar . The name " furfural " comes from lat. furfur - bran, which also indicates the source of this compound. Pyrrole got its name as a characteristic of red color, which acquires a pine sliver when immersed in hydrochloric acid ( dr. Greek pyr - fire ) [1] .
These names do not carry information about the structure of heterocycles, and they are gradually abandoned [1] . Nevertheless, IUPAC recognizes 47 trivial names [K 1] , which can be used to compile the names of more complex condensed heterocycles 
, and 14 more trivial names that are not used for this purpose [2] .
A special case is the nomenclature of some important classes of natural heterocyclic compounds ( carbohydrates and their derivatives, tetrapyrroles and corrinoids ), based on trivial names and codified by the joint commission of IUPAC and the International Union of Biochemistry and Molecular Biology (IUBMB) [3] .
Gancha Nomenclature - Widman
In 1887 and 1888, Ganch [4] and Widman [5] independently proposed naming rules for nitrogen-containing five- and six-membered monocyclic heterocycles. Despite the difference in details (the order of precedence of heteroatoms and the indication of positions in the cycle), both nomenclatures were based on the same principle: a combination of prefixes pointing to the heteroatoms with a base [K 2] indicating the size of the cycle. These principles, supplemented by an indication of the degree of unsaturation of the cycles, formed the basis of the modern version of the Gancha - Widman nomenclature adopted by IUPAC in 1940 and has since undergone several revisions.
At present, prefixes have been developed to denote various heteroatoms, including metals . They are formed from the names of the elements ending in - a (for this reason they are sometimes called a- prefixes). For example, nitrogen , oxygen and sulfur are denoted by the prefixes aza -, oxa - and thia - respectively. If two identical heteroatoms are present in the cycle, then this is reflected in the name with the prefixes di -, three -, tetra - etc. [6]
| Heteroatom | Valence | Prefix | Heteroatom | Valence | Prefix |
|---|---|---|---|---|---|
| Fluorine (F) | one | fluoro- | Arsenic (As) | 3 | arsa |
| Chlorine (Cl) | one | chlorine | Antimony (Sb) | 3 | stiba |
| Bromine (Br) | one | bromo- | Bismuth (Bi) | 3 | bisma |
| Iodine (I) | one | iodine | Silicon (Si) | four | strength- |
| Oxygen (O) | 2 | oxa | Germanium (Ge) | four | herma |
| Sulfur (S) | 2 | thia- | Tin (Sn) | four | stanna- |
| Selenium (Se) | 2 | Selena- | Lead (Pb) | four | plumba |
| Tellurium (Te) | 2 | tellurium | Boron (B) | 3 | bora |
| Nitrogen (N) | 3 | aza- | Mercury (Hg) | 2 | mercury |
| Phosphorus (P) | 3 | phosphate |
The name base is assigned to the heterocycle depending on the size of the cycle, as well as on the hetero atoms contained in it: for nitrogen-containing heterocycles, a separate set of bases is often used. For saturated and maximally unsaturated heterocycles, various sets of bases are also used. Special bases are also sometimes used to indicate partial unsaturation of the heterocycle. For example, saturated nitrogen-free heterocycles get the basics [6] :
- - Iran (for a three-membered cycle),
- - ethane (for a four-membered cycle),
- - olan (for a five-membered cycle),
- - en (for a six-membered cycle), etc.
An example of the use of various bases in the construction of the names of heterocyclic compounds can serve as saturated oxygen-containing heterocycles.
oxiran
oxetane
oxolane (more often: tetrahydrofuran )
oxane (more often: tetrahydropyran )
Replacement Nomenclature
The substitution nomenclature ( a- nomenclature [8] ) considers the heterocyclic compound as the corresponding carbocyclic compound in which one or more carbon atoms are replaced by heteroatoms. With this consideration, the heterocycle gets the name of this carbocycle with prefixes called heteroatoms, and locants (numbers) that indicate their position. For example, pyridine in this nomenclature is called azabenzene. There are many prefixes for designating heteroatoms [9] ; some of them are also used in the Gancha – Widmann nomenclature . Unlike the Gancha – Widman nomenclature , locants according to the replacement nomenclature are indicated before each prefix separately, and not all together at the beginning of the name [10] .
Replacement nomenclature is more convenient for compounds containing heterocycles of various types and, especially, for complex systems [11] . In addition, it represents a more systematic approach to the compilation of names, since only minimal processing of the existing nomenclature rules applicable to carbocycles is necessary [12] .
This type of nomenclature is also used to compose the names of heterocycles with positively charged heteroatoms. The difference is that prefixes of the type oxa -, aza -, thia - are replaced by oxonia -, azonia -, thionia - and so on. In the name, these prefixes immediately follow the prefixes denoting uncharged heteroatoms ( oxonia - after oxa -, thionia - after thia - and so on) [13] .
Compounding titles
Nomenclature of Condensed Heterocycles
Many heterocyclic compounds contain two or more condensed cyclic fragments; therefore, it is often necessary to name heterocycles for which a trivial name is not accepted. For these purposes, a nomenclature of condensed heterocycles has been developed, which is included in the general nomenclature of condensed cyclic systems [14] . According to the recommendations of this nomenclature, a condensed heterocyclic system is divided into two or more component heterocycles and carbocycles, each of the parts is given a separate name, after which these names are combined in the name of the condensed heterocycle with the indication of the places of the junction of the cycles indicating, if any, bridging atoms and groups .
Main cycle selection
If a condensed heterocyclic compound cannot be called the trivial name accepted by IUPAC (for example, indole ), then it must be broken down into smaller components and each component named separately. In this case, it is necessary to determine which of them is the main and which is secondary: the main component is indicated as the root of the name, and the secondary component is in the form of a prefix. To determine the main loop, a set of rules is used that are applied sequentially, one after another, to the connection, until one allows to distinguish between the main and the side loop [15] .
| room | The rule | Illustration [K 3] |
|---|---|---|
| one | If the compound has only one cycle containing a nitrogen atom , then this cycle is the main one. | |
| 2 | If there is no nitrogen atom in both cycles, then the main cycle is the one whose heteroatom is older (according to the table of prefixes from the Ganch-Widman nomenclature). | |
| 3 | If the molecule consists of more than two cycles, then the main component is considered to contain a larger number of cycles . | |
| four | If two cycles have different sizes, then the main one is a larger cycle. | |
| five | If the cycles have a different number of heteroatoms , then the main cycle is considered to be for which this number is greater. | |
| 6 | If the cycles contain the same number of heteroatoms, then the main cycle is considered to be with their greater diversity . | |
| 7 | If the cycles have different heteroatoms, then the cycle with a higher sequence number of heteroatoms is the main one. | |
| eight | The main cycle is considered in which the heteroatoms have the smallest locants (before joining). |
Title Compilation
The name of the cycle, which is chosen as the main one, becomes the root of the new name, and the name of the side cycle becomes the prefix. The prefix is formed by adding a vowel - o to the name of the side heterocycle, for example, pyrazine becomes pyrazino- . There are exceptions for which the prefix is formed with the abbreviation of the name [17] :
- isoquinoline → isoquino- ;
- imidazole → imidazo ;
- pyridine → pyrido ;
- thiophene → thieno ;
- furan → furo ;
- quinoline → quino .
Between the prefix and the root, the sides are recorded by which the two cycles are connected. For this, the sides of the main heterocycle are denoted by the Latin letters a , b , c , d , etc. (starting from the side usually numbered as 1,2-), and the sides of the second component are numbered in the usual way - by locants of the forming atoms (for example, 1, 2-, 2,3-, etc.). The connected sides are written in square brackets through a hyphen, and the numbering of the side of the side heterocycle is written in the exact order in which its atoms occur in the main heterocycle. So, in the given example, the numbering is indicated by 3.2-, rather than 2.3-, because when moving along the atoms of the main heterocycle (furan) from the first to the fifth, the third atom of the thiophene cycle first appears, and only then the second [18] .
The names of per-condensed heterocyclic systems are compiled in a similar way (unlike ortho- condensed heterocycles, the cycles in a per-condensed heterocyclic compound have more than one common side). In this case, it is necessary to list all the atoms and sides of the joint in the order in which they occur when going around the main cycle [19] .
Condensed Heterocycle Numbering
After compiling the name, the condensed heterocycle is numbered anew as a whole compound. Usually, the numbering begins with an atom adjacent to the place of junction of the cycles, but so that the heteroatom gets the lowest number. In uncertain cases, the smallest number should be assigned to the older heteroatom, that is, one that is higher in the prefix table according to the Gancha - Widman nomenclature . Carbon atoms belonging to two cycles are assigned numbers with the index a [20] .
Nomenclature of heterocyclic spiro compounds
Heterocyclic spiro compounds , which consist of two monocyclic parts, are called by adding to the names of the corresponding carbocyclic spiro compounds a- prefixes used in the replacement nomenclature. In this case, the names of carbocyclic spiro compounds are compiled according to the usual rules: a substance is named according to the number of carbon atoms in both cycles with the addition of spiro and the number of carbon atoms in each cycle (not counting the spiro atom) in square brackets, for example, spiro [4,5] Dean The numbering of the heterocycle is carried out as usual in the case of spiro compounds, but so that the heteroatom gets the lowest number if possible. Accordingly, the heterocyclic analog in this case will be called 1-oxaspiro [4,5] decane [21] .
If the heterocyclic spiro compound consists of more complex spiro-compound components, then the names of these components are enclosed in square brackets in alphabetical order, and the spiro - prefix is placed in front of the brackets. The position of the spiroatom is indicated by locants between the names of the components of the spiro system [21] .
Another option is also possible, when using which a larger fragment of the molecule is called the first, then comes the fragment - spiro - and the name of the second cyclic fragment. If necessary, locants indicating the position of the spiroatom are located on both sides of the fragment — spiro - [22] .
Nomenclature of heterocyclic ensembles
Ensembles of identical heterocycles are called by placing the multiplying prefix bi -, three -, tetra - in front of the name of the heterocycle or radical. Such a system is numbered in the same way as the corresponding heterocycle, with the first component of the ensemble being numbered without strokes, the second with one stroke, the third with two strokes, etc. The connection points of the cycles are indicated with digital locants. Other structural features are indicated in the same way as hydrocarbon ensembles [23] .
Nomenclature of hetero-bridges
Heterobridges in cyclic compounds can be designated using special prefixes starting with epi and containing an indication of the radical of which the bridge consists. Thus, bridged oxygen —O— is denoted by an epoxy prefix, a bridge –OO– by an epidioxy prefix, and bridged sulfur –S– and nitrogen –N– by epitio and epimino prefixes , respectively [24] . Similar consoles have been developed for a number of other hetero-bridges [25] . The location of the hetero bridge is indicated by two locants in front of the epi - prefixes. A feature of these prefixes is that they are inseparable from the root of the name (like prefixes like dihydro -), therefore they do not obey the general rules for arranging prefixes in alphabetical order [24] .
Heterocycle atom numbering
The simplest cases
The numbering of atoms in monocyclic compounds is determined by the position of the heteroatom: it always gets the first number. In the presence of several identical heteroatoms, the numbering of the cycle is carried out starting from one of them, so as to obtain the smallest set of locants [K 4] . If the heterocycle contains various heteroatoms, then the numbering begins with the older heteroatom, that is, the heteroatom located above in the prefix table. As in the previous case, among the possible numbering options, choose the one that gives all heteroatoms the smallest set of locants [26] .
Orientation Rules
The numbering of condensed heterocyclic systems is a more difficult task. In this case, before numbering, it is necessary to correctly orient the heterocycle molecule, otherwise it will be impossible to number the atoms in a unique way. The orientation rules of heterocyclic systems completely coincide with those for carbocyclic compounds [27] .
When the molecule of the compound is oriented, it can be rotated in the image plane, and also turned over like a page of a book. In this case, the preferred orientation is established by a set of rules that must be applied in order of priority until an unambiguous decision is made. First of all, they try to arrange the structural formula so that the maximum number of rings appears in a horizontal row. Then, the formula is oriented so that the highest number of cycles appears in the upper right quadrant . In this case, for greater clarity, dissection of the horizontal and vertical axes is used. These axes are drawn through the middle of the horizontal series of cycles defined in the first rule. If any ring appears to be dissected by one or two axes, it is taken into account as two halves or four quarters. For example, in the illustration to rule 3 for both formulas, 1.75 rings are in the upper right quadrant. If the previous rules did not give an unambiguous answer to the question about the desired orientation, the cycle is oriented so that the minimum number of rings is in the lower left quadrant. Finally, the last rule states that the orientation in which the maximum number of rings is above the horizontal row is preferred [28] .
| room | The rule | Illustration [K 5] |
|---|---|---|
| one | The maximum number of rings in a horizontal row. | |
| 2 | The maximum number of rings in the upper right quadrant. | |
| 3 | The minimum number of rings in the lower left quadrant. | |
| four | The maximum number of rings is above the horizontal row. |
Peripheral Numbering
The numbering of the peripheral atoms of a correctly oriented heterocyclic system starts from the very top ring, and if there are several such rings, then from the rightmost one. The first number is assigned to the atom of this cycle, adjacent to the junction of the cycles and located in the extreme position counterclockwise. Numbering is done clockwise around the perimeter of the entire system. Carbon atoms included in two or more cycles do not receive their own number, but are numbered in the same way as the previous numbered atom, with the addition of the letters a , b , c , etc. [29]
Internal Numbering
Heteroatoms that are not on the periphery of the molecule are numbered, continuing the numerical sequence set in the peripheral numbering. In this case, the heteroatom, which is closer to the peripheral atom with the lowest number, is numbered first. Internal carbon atoms receive the same locants as the nearest peripheral atoms, but with a superscript indicating the number of bonds between the corresponding internal and peripheral atoms. If there is a choice, then the smallest possible locant is assigned to the internal carbon atom [30] .
Nomenclature of heterocyclic radicals
The names of monovalent heterocyclic radicals are formed from the names of the corresponding heterocyclic compounds by adding the suffix - silt , for example, indolyl , triazolyl . Nevertheless, some exceptions remain for this rule [31] :
- isoquinoline → isoquinolyl ;
- piperidine → piperidyl ;
- pyridine → pyridyl ;
- thiophene → thienyl ;
- furan → furyl ;
- quinoline → quinolyl .
As an exception, the names piperidino and morpholino are preferred over 1- piperidyl and 4- morpholinyl [31] .
The names of divalent radicals are formed by a similar addition of the suffix - Eden . To form the names of multivalent radicals, suffixes - diyl , - triyl are used , added to the name of the compound [31] .
The names of radicals derived from heterocyclic spiro compounds are called according to the general rules with the addition of suffixes - silt , - diyl , etc. [32]
Nomenclature of heterocyclic anions
The simplest way to compose the name of a heterocyclic anion is to add to the name of the corresponding radical the word anion (for example, imidazolyl anion). Such a nomenclature is convenient if anions themselves are considered as individual particles. In other cases, you can apply rules similar to those used to compile the names of radicals. If a heterocyclic anion can be obtained by detaching a proton (protons) from a certain heterocycle, then the suffix is id to the name of this heterocycle (- a diid - when two protons are detached, etc.), and the proton detachment site is indicated by a locant, for example, imidazole - 1-id From the obtained name of the fully unsaturated heterocyclic anion, one can compose the name of its partially or fully hydrogenated analogue [33] .
Sometimes heterocycle anions are formed when a proton is cleaved not from a ring atom, but from a substituent in the ring, for example, from a carboxyl , hydroxyl , thiol or amino group . In this case, the names are formed according to the general rules for the corresponding classes of compounds using the suffixes - carboxylate , - olate , - thiolate and - aminyl (- amide ) [34] .
Nomenclature of heterocyclic cations
By analogy with anions, the chemistry of heterocycles deals with heterocyclic cations in which a positive charge is not only on the atoms of the ring, but also on the atoms of the substituents. Accordingly, various types of nomenclature are used.
The cations obtained by the formal attachment of a proton to a heteroatom of a ring are called by adding a suffix to the heterocycle name with the locant. In obvious cases, the locant is optional (1,4-dioxania, pyridinium). Similarly, cations obtained by attaching a proton to a side functional group (- amidium , - imidium , - nitrile , - amine ) are also called [35] .
The cations obtained by the formal cleavage of the H hydride ion from the heterocyclic compound are called by the suffix - ily (furan-2-ile) [36] .
Heterocyclic cations with a charge on the heteroatom can be called by substitution nomenclature replacing prefixes of the type oxa -, aza -, thia - with oxonium -, azonia -, thionia - etc. [13] [37]
Nomenclature of heterocyclic zwitterions
If the cationic and anionic centers are in the same molecule, then such a structure is called a zwitterion . If both of these centers are in the same parent heterocycle, then the suffixes described above characteristic of the names of cations and anions are added to the name of this heterocycle, and the anionic suffixes are placed after the cationic ones. If one of the ionic centers is located on the side substituent denoted by a suffix, then appropriate suffixes are also used, as described above [38] .
Designated Hydrogen
In the case of some heterocyclic compounds containing the maximum number of double bonds , the arrangement of these bonds may be different. For this reason, for cycles with the same heteroatoms and the same size, there may exist isomers differing in the position of double bonds. To distinguish between such isomers, the concept of designated hydrogen was introduced, in which a cycle atom not included in the double bond system, that is, containing "excess" hydrogen, is indicated by the prefix H - with a locant corresponding to the position of this atom. For example, for azirin, there are two isomers with a different arrangement of the double bond: if the nitrogen atom is not included in the double bond (according to the numbering of the cycle, having locant 1), then such azirin is denoted by 1 H - azirine . Accordingly, azirin, in which a carbon atom is not included in the double bond, is called 2 H - azirin [39] .
When numbering the atoms of the cycle, the designated hydrogen should receive the lowest possible number: in this, it has an advantage over the highest functional group or radical valency [40] .
λ-Notation
Hetero atoms in heterocyclic compounds can have different valencies , for example, phosphorus can be either trivalent or pentavalent. Moreover, the most common valencies in organic compounds are considered standard . All other valencies are called non-standard and require special designation in the names. Heteroatoms in non-standard valencies are denoted by the symbol λ-, indicating the value of its valency, that is, the number of bonds by which the heteroatom is bonded to other atoms [41] .
| Valence | Atoms |
|---|---|
| four | C , Si , Ge , Sn , Pb |
| 3 | B , N , P , As , Sb , Bi |
| 2 | O , S , Se , Te , Po |
| one | F , Cl , Br , I , At |
The symbol λ is located before the name of the heterocycle, immediately after the locant of the corresponding heteroatom. If the locants are not used in the standard spelling, then the necessary locant can be indicated before the name. In the names of condensed heterocyclic compounds, the symbol λ is set for the whole system, and not for individual components [41] .
λ-Designations are a universal system for designating non-standard valencies in the chemical nomenclature and apply not only to heterocyclic compounds [41] .
Comments
- ↑ In the latest versions of the rules for such names, 45 remained, but the number 47 is given in various manuals on the nomenclature and chemistry of heterocyclic compounds.
- ↑ In various sources, the English word stem , denoting this part of the name of the compound, is transmitted by Russian analogues to the base , root or suffix . This is probably due to differences in the morphology of Russian and English words. In his book, Ramsh expresses the opinion that stem is incorrectly regarded as a basis, since stem consists of a root denoting the size of the cycle and a suffix denoting its degree of unsaturation, while the prefix is also the basis of the word in Russian.
- ↑ The main heterocycle is shown in blue in the figure.
- ↑ In this case, we have in mind this method of comparing sets of locants, in which these sets are written in the order of increasing their members, and then they are compared in pairs. A smaller set is one with the first different member less. Sometimes it is mistakenly believed that it is necessary to compare the sums of sets of locants.
- ↑ The preferred orientation is shown in blue in the figure.
Notes
- ↑ 1 2 Gilchrist, 1996 , p. 442.
- ↑ Kahn, Dermer, 1983 , p. 112-117.
- ↑ IUPAC-IUBMB White Book: Biochemical Nomenclature and Related Documents
- ↑ Hantzsch A., Weber JH Ueber Verbindungen des Thiazols (Pyridins der Thiophenreihe) // Berichte der deutschen chemischen Gesellschaft. - 1887. - T. 20 , No. 2 . - S. 3118-3132 . - DOI : 10.1002 / cber.188702002200 .
- ↑ Widman O. Zur Nomenclatur der Verbindungen, welche Stickstoffkerne enthalten // J. Prakt. Chem. - 1888. - T. 38 , No. 1 . - S. 185-201 . - DOI : 10.1002 / prac.18880380114 .
- ↑ 1 2 Gilchrist, 1996 , p. 445.
- ↑ IUPAC, 1983 .
- ↑ ACDLabs. Heterocyclic Systems. Rule B-4. Replacement Nomenclature (also known as "a" Nomenclature) . Date of treatment May 14, 2013. Archived May 22, 2013.
- ↑ ACDLabs. Appendix. R-9.3 "a" Prefixes Used in Replacement Nomenclature . Date of treatment May 14, 2013. Archived May 22, 2013.
- ↑ Ramsch, 2009 , p. 102.
- ↑ Kahn, Dermer, 1983 , p. 121.
- ↑ Gilchrist, 1996 , p. 450.
- ↑ 1 2 ACDLabs. Heterocyclic Systems. Rule B-6. Cationic Hetero Atoms . Date of treatment May 14, 2013. Archived May 22, 2013.
- ↑ Moss GP Nomenclature of fused and bridged fused ring systems (IUPAC Recommendations 1998) // Pure & Appl. Chem. - 1998. - T. 70 , No. 1 . - S. 143-216 .
- ↑ 1 2 Gilchrist, 1996 , p. 449-450.
- ↑ ACDLabs. Heterocyclic Systems. Rule B-3. Fused Heterocyclic Systems . Date of treatment May 14, 2013. Archived May 22, 2013.
- ↑ Gilchrist, 1996 , p. 447.
- ↑ Gilchrist, 1996 , p. 447-448.
- ↑ Ramsch, 2009 , p. 52.
- ↑ Gilchrist, 1996 , p. 448.
- ↑ 1 2 ACDLabs. Heterocyclic Spiro Compounds. Rule B-10. Compounds: Method 1 . Date of treatment May 16, 2013. Archived May 22, 2013.
- ↑ ACDLabs. Heterocyclic Spiro Compounds. Rule B-11. Compounds: Method 2 . Date of treatment May 16, 2013. Archived May 22, 2013.
- ↑ ACDLabs. Heterocyclic Ring Assemblies. Rule B-13 . Date of treatment May 16, 2013. Archived May 22, 2013.
- ↑ 1 2 Kahn, Dermer, 1983 , p. 122.
- ↑ ACDLabs. Bridged Heterocyclic Systems. Rule B-15. Hetero Bridges . Date of treatment May 18, 2013. Archived May 22, 2013.
- ↑ Ramsch, 2009 , p. 27-29.
- ↑ Ramsch, 2009 , p. 77.
- ↑ 1 2 Ramsh, 2009 , p. 80-82.
- ↑ Ramsch, 2009 , p. 81.
- ↑ Ramsch, 2009 , p. 87-88.
- ↑ 1 2 3 ACDLabs. Heterocyclic Systems. Rule B-5. Radicals . Date of treatment May 14, 2013. Archived May 22, 2013.
- ↑ ACDLabs. Heterocyclic Spiro Compounds. Rule B-12. Radicals . Date of treatment May 16, 2013. Archived May 22, 2013.
- ↑ Ramsch, 2009 , p. 158.
- ↑ Ramsch, 2009 , p. 160.
- ↑ Ramsch, 2009 , p. 178-181.
- ↑ Ramsch, 2009 , p. 184.
- ↑ Ramsch, 2009 , p. 194.
- ↑ Ramsch, 2009 , p. 230-232.
- ↑ Kahn, Dermer, 1983 , p. 142.
- ↑ Kahn, Dermer, 1983 , p. 151.
- ↑ 1 2 3 4 Treatment of variable valence in organic nomenclature (λ-notation) . Date of treatment May 19, 2013. Archived May 22, 2013.
Literature
- Gilchrist T. Chemistry of heterocyclic compounds = Heterocyclic Chemistry / Per. from English A.V. Karchava and F.V. Zaitseva, ed. M.A. Yurovskaya. - M: Mir, 1996 .-- S. 441-451. - ISBN 5-03-003103-0 .
- Kahn R., Dermer O. Introduction to Chemical Nomenclature = Introduction to Chemical Nomenclature / Per. from English N. N. Shcherbinovskaya, under the editorship of V. M. Potapova, R. A. Lidina. - M: Chemistry, 1983.- 224 p.
- Ramsh S.M. Guide to the compilation of the names of heterocyclic compounds with examples and tasks. - St. Petersburg: Khimizdat, 2009 .-- 406 p. - ISBN 978-5-93808-173-4 .
- Comission on nomenclature of organic chemistry. Revision of the extended Hantzsch-Widman system of nomenclature for heteromonocycles . - 1983. - Vol. 55 , no. 2 . - P. 409-416 . - DOI : 10.1351 / pac198855020409 . Archived on June 10, 2015.