by Historical Background
It was first isolated in 1826 by German chemists Otto Unverdorben and Friedlieb Runge through the destructive distillation of indigo. They named the new substance “kyanol” based on its color. In 1834, German chemist Erdmann named it “aniline” derived from the Ancient Greek word anilinon, which means indigo. Early uses of it included medicinal purposes to relieve pain and fever. Commercial production began in 1856 when William Henry Perkin synthesized the first synthetic dye made from it – mauveine, also known as aniline purple. This kickstarted the its dye industry and marked the beginning of the synthetic dye industry.
Manufacturing Process
It is produced industrially through two main routes – the reduction of nitrobenzene or the reaction of chlorobenzene with ammonia. In the nitrobenzene reduction process, nitrobenzene is reacted with hydrogen over a nickel catalyst at high temperatures and pressures. This converts the nitro group to an amine group to produce it. In the chlorobenzene process, chlorobenzene reacts with ammonia in the presence of a nickel/alumina catalyst to substitutes the chlorine with an amine group. Both routes result in it as the main product along with other byproducts such as phenol that require further purification steps. The purified Aniline can then be used to manufacture numerous dyes, drugs, and plastics.
Applications in Dyes
Almost 90% of the world’s production is used for the manufacture of dyes and dye intermediates. This is because it was the starting building block for many synthetic dyes developed in the late 19th century. Some examples of dyes derived from it include:
– Methyl Violet: One of the first synthetic dyes made from it. It is used to dye paper, silk, leather and other materials.
– Chrysamine G: A triarylmethane dye used as a pH indicator and in stain formulations. It imparts yellow color.
– Congo Red: A azo dye used for dyeing cotton, wool and silk. It is also used as a histological stain.
– Nigrosin: A black non-toxic dye used for staining specimens on microscope slides.
– Acid Blue 90: A triazine dye used for cotton dying that imparts intense blue shades.
It continues to play a crucial role in the dye industry due to the wide array of colors that can be obtained by coupling it with other organic compounds. New dyes are constantly being developed to meet industrial and consumer needs.
Pharmaceutical Applications
About 5-10% of it produced is utilized in the pharmaceutical industry for manufacturing key drugs. Some examples include:
– Paracetamol (Acetaminophen): The most widely used over-the-counter pain reliever and fever reducer. It is used as a starting material in its production.
– Imatinib: A drug used in the treatment of certain cancers like chronic myeloid leukemia. It is derived from it in its manufacturing process.
– Pheniramine: An antihistamine used to treat allergic reactions like hay fever. It contains a substituted its group in its structure.
– Lidocaine: A local anesthetic injected during minor surgery or dental work. It contributes to its synthesis.
– Dapsone: An antibiotic used to treat leprosy and dermatitis herpatiformis. It is synthesized using it as a starting material.
Research into new aniline-based drug molecules is ongoing due to its aromatic and amine functional groups that make it a suitable building block.
Use in Plastics and Polymers
Approximately 5-10% of it manufactured is used in the production of various plastics, polymers and synthetic fibers. Some examples are:
– Methylene Diphenyl Diisocyanate (MDI): Used to produce polyurethane flexible and rigid foams for applications like furniture, insulation and automotive. It is a precursor.
– Spandex: The fiber used to make elastic materials like socks and clothing. It is polymerized using it.
– Nylon: A widely used synthetic fiber with applications from fabrics to industrial uses like ropes and tires. It is involved in some nylon production processes.
– Melamine resins: Used to manufacture decorative laminates, tableware and white goods. Its synthesis involves it.
It provides chemical intermediates for various plastics due to its reactivity. Ongoing research aims to develop new aniline-derived polymers with improved properties.
Health and Environmental Considerations
While it has proved indispensable in industry, it also poses certain health and environmental risks that require management. Prolonged occupational exposure may cause methemoglobinemia or “blue disease” by interfering with blood’s oxygen transport. It is also linked to cancers in laboratory animals. As such, its use entails proper handling techniques and safety precautions. It is toxic to aquatic life and may persist in water systems if not treated before disposal. Governments regulate its manufacture, transportation, storage and disposal through environmental laws. Overall, as a high volume chemical, responsible production and use of it aims to balance its benefits with minimizing associated impacts.
it has come a long way from its origins as an unexpected byproduct of indigo manufacturing. Its unique reactivity profile has enabled its wide use across industries from dyes to pharmaceuticals and plastics. Though health and environmental issues necessarily accompany its large-scale synthesis, aniline remains a cornerstone building block for both established and emerging commercial products. Ongoing research explores optimizing current aniline chemistries along with discovering new applications for this aromatic amine.
*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
Ravina Pandya, a content writer, has a strong foothold in the market research industry. She specializes in writing well-researched articles from different industries, including food and beverages, information and technology, healthcare, chemicals and materials, etc. With an MBA in E-commerce, she has expertise in SEO-optimized content that resonates with industry professionals.
