Preparation of Carboxylic acids

The compound in which the carbonyl group is affixed with the hydroxyl group then it is known as Carboxylic acid. There are various processes by which we can prepare Carboxylic acids.

By using primary Alcohols and Aldehyde

Primary alcohol gets oxidized to carboxylic acid when oxidizing agents such as potassium permanganate (KMnO4) in alkaline, acidic or neutral medium are added. On using a medium nature of the oxidising agent, we can obtain carboxylic acids from aldehydes.

From Alkylbenzenes

We can obtain aromatic carboxylic acids by robust oxidation of alkylbenzenes in the presence of chromic acid. Regardless of the chain length, the whole side of the chain is oxidized to a carbonyl group. The oxidation of primary as well as secondary alkyl groups can be done by this process while the tertiary group is not affected by the above process.

From Nitriles and Amides

Amides are obtained by the hydrolysis of nitriles and then in the presence of catalysts (H+ or OH-1), it is converted to acids. In order to halt the reaction in-between stages, mild reaction conditions are being used.

• By using Grignard Reagents
  When the Grignard reagent is reacted with carbon dioxide it forms salts of carboxylic acids which after some moments yields corresponding carboxylic acid after it is reacted with any mineral acid. We can obtain nitriles as well as Grignard reagents from alkyl halides. These methods are very functional for the conversion of alkyl halides into appropriate carboxylic acids which have only one carbon atom greater than what is present in alkyl halides.

By Acyl Halides and Anhydrides

When acid chloride is hydrolyzed in the presence of water then carboxylic acid is obtained and it is more rapidly hydrolyzed with a water-soluble base and gives appropriate carboxylic ions which on more acidification produces the carboxylic acid.

By using Esters

After the acidic hydrolysis of esters, the carboxylic acid is produced and after the basic hydrolysis of an ester, carboxylates are produced.

Carboxylic Acid Structure

The formula of a carboxylic acid is that is, it is generally represented by the formula R-COOH, where COOH means to the carboxyl group, and R means to the remaining of the molecule to which this group is bonded. In this carboxyl group, there is present a C which shares a double bond with an O atom and a single bond with a -OH group.

A carboxylic acid is generally has a formula of R-COOH, where COOH denotes the carboxyl group and R denotes the remainder of the molecule to which this group is linked. There is carbon in this carboxyl group that has a double connection with an oxygen atom and a single bond with a hydroxyl group.

The first four carboxylic acids obtain from alkanes are methanoic acid (HCOOH), ethanoic acid (CH3COOH), propanoic acid (C2H5COOH), and butanoic acid (C3H7COOH).

It can be observed that a carboxylic acid contains a hydroxyl group attached to a carbonyl carbon. Due to the electronegativity of the O atom, this functional group can easily undergo ionization and release a proton.

The carboxylate ion, formed from the removal of a proton from the carboxyl group, is stabilized by the presence of two O atoms. Some examples of carboxylic acids are acetic acid and Formic acid.

Nomenclature of Carboxylic Acids

Generally, these organic compounds are denoted by their trivial names, which contain the suffix “-ic acid”. An example of a trivial name which is for a carboxylic acid is acetic acid (CH3COOH).  According to the IUPAC nomenclature of these compounds, the suffix “-oic acid” is assigned.

The guidelines that must be followed in the IUPAC nomenclature of carboxylic acids are listed below.

• The suffix “e” in the name of the given alkane should be replaced with “oic acid”.

• When the aliphatic chain has only one carboxyl group, the carboxylic carbon is always numbered prioritised as one. For example, the compound CH3COOH is named ethanoic acid.

• When the aliphatic chain contains has more than one carboxyl group, the total number of C atoms is counted and the number of carboxyl groups is shown by Greek numeral prefixes such as “di-”, “tri-“, etc.

•  Then this carboxylic acid is named by joining these prefixes and suffixes to the parent alkyl chain. Arabic numerals are used for indicating the positions of the carboxyl group.

• The name “carboxylic acid” or “carboxy” can also be assigned for a carboxyl substituent on a carbon chain. An example of such nomenclature is the name 2-carboxyfuran for the compound 2-Furoic acid.

Uses of Carboxylic Acids

• Fatty acids that are important to human beings constitute carboxylic acids. Examples are given are omega-6 and omega-3 fatty acids.

• In the manufacture of soaps, higher fatty acids are also used.

• Many carboxylic acids are used in the production of soft drinks and many other food products.

• The manufacture of rubber includes the use of acetic acid (coagulant).

• In the manufacture of nylon-6,6 hexanedioic acid is used.

• Carboxylic acids are very useful in the rubber, textile, and leather industries.

• Ethylenediaminetetraacetic acid is a widely used chelating agent.

• The manufacturing of many drugs involves the use of the said compounds. Therefore, carboxylic acids are very essential in pharmaceuticals.

• The manufacturing of many polymers includes the use of compounds in which the carboxyl functional group is present.

Conclusion: –

The carboxylic acids are one of the most important functional groups that present C=O. This type of organic compound can be manufactured by different methods, some carboxylic acids, such as lactic acid, citric acid, or fumaric acid are produced by fermentation. Most of these types of carboxylic acids are used in the food industry.