Naming of Carboxylic Acid Derivatives - JEE Important Topic

We will discuss the naming of carboxylic acid and acid halide T here. Carboxylic acids are commonly named after the number of carbons in the longest continuous chain, including the carboxyl group (-COOH) present in them. Carboxylic acids always end in "-acid", so this carbon chain suffix is ​​replaced. It has various derivatives: acid halides, acid anhydrides, esters, acid amides, phosphate acyl, etc.

Naming of Carboxylic acid Derivatives Compounds

Naming of Acid Halide T, RCOX

• Acid halide nomenclature begins with the name of the corresponding carboxylic acid. 

• If the corresponding carboxylic acid ends with -oic acid or -ic acid, it is removed and replaced with the ending -oyl, followed by the first syllable of the halogen name and the end of -ide.

• However, there are some specific exceptions that allow IUPAC to use the -yl suffix instead.

• Examples include formic acid ⇒ formyl, acetic acid ⇒ acetyl, propionic acid ⇒ propionyl, fatty acid ⇒ butyryl, oxalic acid ⇒ oxalic acid and succinic acid ⇒ succinic acid.

• If the corresponding acid contains the suffix -carboxylic acid, it is removed and replaced with the suffix -carbonyl. 

• This is followed by the first syllable of the halogen name and the -ide ending. The carbonyl carbon is numbered 1. The acid halide functional group is believed to be at the end of the parent chain, so it is not necessary to include the functional group position number in the name.

Anhydride Nomenclature, RCO₂COR '

• When two carboxylic acids combine to lose water, anhydride functional groups are formed (anhydride = no water). 

• The name of the anhydride comes from the name of the two carboxylic acids combined. 

• The carbonyl carbon is numbered 1 on both chains. 

• Anhydrous functional groups are believed to be at the end of each parent chain, so it is not necessary to include the functional group position number in the name.

• Symmetric anhydrides of unsubstituted carboxylic acids and cyclic anhydrides of dicarboxylic acids are named after the corresponding carboxylic acids. 

• The suffix -acid is replaced with -anhydrate. 

• If the anhydrate is acyclic and the acyl R groups are the same, the anhydrate is symmetric.

• Asymmetric anhydrides are formed from two different carboxylic acids. For asymmetric anhydrides, name both acids alphabetically with spaces. 

• Then add the anhydrate for the last word.

Nomenclature of Other Carbonyl Compounds

Ester Nomenclature, RCO₂R '

• Esters are composed of two different carbon chains that need to be named separately. 

• One carbon chain is derived from the corresponding carboxylic acid, and the other chain bound to the single-bound oxygen is called the alkoxyalkyl chain.

• Esters are named as if the alkoxyalkyl chain was a substituent (prefix + yl). 

• This is followed by the name of the corresponding carboxylic acid moiety of the ester, with the -ic or -oic acid replaced by the suffix -ate. 

• The carbonyl carbon is numbered 1. The carbonyl functional group is believed to be at the end of the parent chain, so it is not necessary to include the functional group position number in the name.

Naming of Carboxamide Structure, RCONH₂, RCONHR', RCONR' R''

• Primary amide (RCONH₂) removes the suffix -oic acid or -ic acid and adds -amide to the name of the corresponding acid. 

• Amides derived from cyclic carboxylic acids have the carboxylic acid ends replaced with a carboxamide structure. 

• The carbonyl carbon is numbered 1. 

• The functional group is assumed to be at the end of the parent chain, so it is not necessary to include the site number in the name.

• Secondary (RCONHR') and tertiary (RCONR'R'') amides are named using the capital letter N to indicate that the alkyl group is attached to the nitrogen atom.

• These alkyl groups are called substituents (prefix + yl).

• Cyclic amide is called lactam. 

• The Greek letter indicates the position of nitrogen on the alkyl chain with respect to the carboxyl-carbonyl group.

Phosphate Acyl Nomenclature, RCOOPO₃^2-

• The nomenclature for phosphate acyl is called acid halide according to the rules; except that the word phosphate is used instead of the halogen name. 

• If the alkyl group is attached to one of the oxygen phosphates, it is called the substituent (parent + yl) and is listed before the last word, phosphate.

• When a phosphate ion is attached to a carbon atom of an organic molecule, the chemical bond is called a phosphate ester and the whole species is called organic monophosphate. Glucose-6-phosphate is one example.

• When an organic molecule is attached to two or three phosphate groups, the resulting species are called organic phosphate and organic triphosphate.

• Isopentenyl diphosphate and adenosine triphosphate (ATP) are good examples.

• The oxygen atom of a phosphate group is called "cross-linked" or "non-crosslinked", depending on its position. 

• Organic diphosphate has two crosslinked oxygen atoms and five non-crosslinked oxygen atoms.

• When one phosphate is attached to two organic groups, it is called a "phosphodiester". 

• The term "phosphoryl group" generally refers to all of the above phosphoryl groups.

What Is the IUPAC name of Succinic Acid?

Succinic acid is a dicarboxylic acid, having the chemical formula (CH₂)₂(CO₂H)₂. Its IUPAC Name is Butanedioic acid.

Syllables of Aromatic

• Aromatic has four syllables: ar-o-mat-ic

• Aromatic is divided into syllables: ar-o-mat-ic

• Aromatic emphasis syllables: ar-o-mat-ic

• Next emphasised syllable: ar-o-mat-ic

Summary

The IUPAC name for carboxylic acids comes from the name of the longest carbon chain containing the carboxyl group by removing the last -e in the parent alkane name and adding the word "acid" after the suffix -oic. The chains are numbered, starting with the carbon of the carboxyl group. Acid halides are named according to the IUPAC rules, carboxylic acids end with -oyl or -yl, and halides end with -ide. 

Anhydride is named according to the IUPAC rule, replacing the carboxylic acid suffix -acid with -anhydride. Esters are named according to the IUPAC rules, replacing carboxylic acids ending in -oic acid with -ate and replacing alkoxyalkyl chains as substituents.

Primary amides are named according to IUPAC rules and replace carboxylic acids ending with -oic acid with -amide. Secondary or tertiary amides are called primary amides, but the capital N is used to represent an alkyl group attached to a nitrogen atom called a substituent. Acyl phosphates are named according to IUPAC rules, and carboxylic acids end with -oyl or -yl and -phosphate.