Synthesis and Uses of Paracetamol

Paracetamol: Synthesis and Uses

Paracetamol or acetaminophen was first made in 1878 by Harmon Northrop Morse or possibly in 1852 by Charles Frédéric Gerhardt. It is a non-opioid analgesic and antipyretic agent used to treat fever and mild to moderate pain. It works by blocking the release of certain chemical messengers that cause pain and fever. Paracetamol should be taken with food or milk to prevent upset stomach and should not take medications containing paracetamol if you are allergic to it or any of the other ingredients in the paracetamol product you are taking. It should not take more than the recommended dose. Paracetamol may be taken every 4 to 6 hours. Leave at least 4 hours between doses and should not take more than four doses in 24 hours.

Synthesis of Paracetamol

Paracetamol can be synthesized through various methods, the most common industrial method are given below.

Synthesis of Paracetamol From Chlorobenzene

Synthesis of paracetamol from chlorobenzene is a multi-step process which is shown below-

Synthesis of Paracetamol From Nitrobenzene

Paracetamol can be synthesized from nitrobenzene using Bamberger rearrangement.

Synthesis of Paracetamol From Phenol

Phenol can be nitrated to produce a mixture of ortho- and para-nitrophenol. The para isomer is then isolated and reduced to 4-aminophenol followed by acetylation of the amino group to form an amide linkage, resulting in paracetamol.

Isolation and Purification of Paracetamol

The crude paracetamol needs to be isolated and purified.

Crystallization

The paracetamol product is often a solid that can be separated by filtration. Recrystallization from a suitable solvent (like hot water) is a common purification technique to obtain high-purity paracetamol crystals. This involves dissolving the crude product, heating, then cooling to allow the pure product to crystallize out, leaving impurities in the solution.

Washing and Drying

The purified crystals are then washed to remove any residual impurities and dried.

Uses of Paracetamol

Paracetamol is analgesic and antipyretic agent used to treat fever and mild to moderate pain. It is used to relieve pain in conditions like headache, muscle pain, or dental pain. The paracetamol tablet can be use in the following conditions:

1. Headaches
2. Menstrual period
3. Body ache
4. Toothache
5. Osteoarthritis
6. Backaches
7. Fever
8. Arthritis pain
9. Cold

Paracetamol is generally safe. Pregnant or breastfeeding women and children over two months old can take it.