Suffixes naming acids

When a carboxyl group is attached to a ring the parent ring is named (retaining the final e) and the suffix carboxylic acid is added as shown m entries 8 and 9... 

Compounds with two carboxyl groups as illustrated by entries 10 through 12 are distinguished by the suffix dioic acid or dicarboxylic acid as appropnafe The final e m fhe base name of fhe alkane is refamed... 

The names of amides of the type RCNH2 are derived from carboxylic acids by replacing the suffix oic acid or ic acid by amide... 

As usual, R is a hydrocarbon group or, in the simplest case, a hydrogen atom. The acidic hydrogen atom is the one bonded to oxygen. The IUPAC name of a carboxylic add can be obtained by substituting the suffix -oic acid for the final e in the name of the corresponding alkane. In practice, such names are seldom used. For example, the first two members of the series are commonly referred to as formic add and acetic add. 

Carboxylic acids are named systematically by replacing the -e of the parent hydrocarbon by the suffix -oic acid the carbon atom of the carboxyl group is included in the count of atoms to determine the parent hydrocarbon molecule. Thus, formic acid is formally methanoic acid, and acetic acid is ethanoic acid. 

The aldehyde signature, -C-H (written also as -CHO, but never -COH), is always located at the end of the carbon chain. Common names for aldehydes are derived from the corresponding acid to which they are converted by further oxidation. The suffix ic acid is simply changed to -aldehyde ... 

Since carboxylic acids are amongst the earliest organic compounds to be isolated from nature, a large number of them are known by their common names. The common names end with the suffix -ic acid and have been derived from Latin or Greek names of their natural sources. For example, formic acid (HCOOH) was first obtained from red ants (Latin formica means ant), acetic acid (CH C OOH) from vinegar (Latin acetum, means vinegar), but n ic acid (CH3CH2CH2COOH) from rancid butter (Latin butyrum, means butter). 

The suffixes -oic acid, -al, -amide and -nitrile are used to name acyclic compounds having one or two characteristic groups. Locants are not necessary, as these groups must be at the end of a chain. The suffixes -carboxylic acid, -carbaldehyde, -carboxamide and -carbonitrile are used when more than two groups are attached to chains or one or more groups are attached to cycles. 

Aliphatic dicarboxylic acids are named by simply adding the suffix -dioic acid to the root name. The root name comes from the longest carbon chain containing both carboxyl groups. Numbering starts at the end closest to a substituent. 

In addition to the oxoacids, there are a small number of other acids, such as HC1, that do not contain oxygen. Although the pure, gaseous compound HC1 is named hydrogen chloride according to the rules for binary compounds, the aqueous solution is named hydrochloric acid, HCl(a ). This example is typical of non-oxygen-containing acids The prefix hydro- and the suffix -ic acid are used for the aqueous solution in such cases. 

To name an acid, look at the formula and decide whether the compound is an oxoacid. If so, the name must reflect the number of oxygen atoms, according to Table 2.4. If the compound is not an oxoacid, it is named using the prefix hydro- and the suffix -ic acid. 

C The COOH group means that the molecule is a carboxylic acid and its name will use the suffix -oic acid. The presence of 4 carbon atoms means the prefix butan- will be used. An alternate name for the molecule is butyric acid. Choices A and B would be used for aldehydes (CHO group). Choices B and D would be used for 3 carbon atoms ... 

Common names for simple aldehydes are frequently encountered. These common names are derived from the common names for the related carboxylic acid (see Section 12.4) by replacing the suffix -ic acid with the suffix -aldehyde. Thus, the aldehyde related to acetic acid is acetaldehyde. If the carbonyl group of an aldehyde is attached to a ring system, the compound can be named as a hydrocarbon with the suffix -carbaldehyde. (Some sources use -carboxaldehyde.)... 

Chlorocyclopentanecarboxylic acid (In similar fashion to the use of the -carbaldehyde suffix in naming aldehydes, cyclic compounds with the carboxy group attached to the ring use the name of the ring with the suffix -carboxylic acid.)... 

The suffix -sulfonic acid is added to the hydrocarbon name.)... 

The IUPAC nomenclature for carboxylic acids uses the name of the alkane that corresponds to the longest continuous chain of carbon atoms. The final -e in the alkane name is replaced by the suffix -ok acid. The chain is numbered, starting with the carboxyl... 

Common names of nitriles are derived from the corresponding carboxylic acids. Begin with the common name of the acid, and replace the suffix -ic acid with the suffix -onitrile. The IUPAC name is constructed from the alkane name, with the suffix -nitrile added. 

Compounds that have a carboxylic acid bonded to a ring are named by using the suffix -carboxylic acid. 

The heading parent, e.g., 2-butenoic acid, consists of a molecular skeleton (2-butene) and a suffix (-oic acid) detailing the principal functional group. There can only be one functional group in any one name. (Note elision of the terminal -e in butene.) Where there is no functional group, the heading parent consists only of a molecular skeleton name, e.g., methane, pyridine. 

An acid can be viewed as a molecule with one or more H+ ions attached to an anion. The rules for naming acids depend on whether the anion contains oxygen. If the anion does not contain oxygen, the acid is named with the prefix hydro- and the suffix -ic. For example, when gaseous HC1 is dissolved in water, it forms hydrochloric acid. Similarly, HCN and H2S dissolved in water are called hydrocyanic and hydrosulfuric acids, respectively. 

A common name is formed by using a common parent name followed by the suffix -/c acid. 

Many compounds containing two carboxy groups are also known. In the lUPAC system, diacids are named by adding the suffix -dioic acid to the name of the parent alkane. The three simplest diacids are most often identified by their common names, as shown. 

Alternatively, compounds that have a -COOH group bonded to a ring are named using the suffix -carboxylic acid. The COOH carbon is attached to Cl and is not itself numbered in this system. 

An anion derived from a ternary acid with an -ic ending is named by dropping the -ic acid and replacing it with -ate. An anion derived from an -ous acid is named by replacing the suffix -ous acid with -ite. The per- and hypo- prefixes are retained. 

If a carboxylic acid contains a carboxyl group at each end of the chain, the suffix -dioic acid is added to the name of corresponding alkane. 

From the —COOH group, H+ ion leaves and a carboxylate salt forms. To obtain the name of carboxylate anion, the suffix -oic acid is replaced by the suffix -ate. For example, CH3COO is called acetate. 

Carboxylic acids are almost always named using a suffix. The suffix oic acid is attached to the name for the longest continuous carbon chain. If the acid group is attached to a ring the suffix carboxylic acid is used. 

Carboxylic acids are named by adding the suffix oic acid to the base name. Acid chlorides are name by changing the ic acid of the parent carboxylic acid to yl chloride. The suffix acid is changed to anhydride to name acid anhydrides. Esters are named like acid salts by changing ic acid to ate and preceding the name by the name of the alkyl group. To name amides, the oic acid is changed to amide. 

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