Difference between revisions of "Aniline"

Revision as of 21:01, 6 June 2018

Aniline, also known as aminobenzene or phenylamine is an aromatic organic compound, the simplest aromatic amine. It has the chemical formula C₆H₇N or more convenient C₆H₅NH₂.

Properties

Chemical

Aniline can be oxidized with potassium permanganate to nitrobenzene. This reaction is the opposite of aniline's synthesis.

Physical

Aniline is a colorless liquid with a strong ammonia or fish-like odor. It is miscible with water and most organic solvents.

Availability

Aniline is sold by various chemical suppliers, though it's not easy to obtain.

Preparation

There are several ways to make aniline. The most common way involves the reduction of nitrobenzene with hydrogen in the presence of a metal catalyst.

Another method of obtaining aniline is through the destructive distillation of Indigo.

Projects

• Make trinitroaniline

Handling

Safety

Aniline is toxic in large quantities and it's best to avoid being exposed to it for too long.

Storage

Aniline should be stored in closed bottles, best in amber glass bottler with a PTFE lining, away from any source of ignition and copper alloys. Due to its foul smell, it's best to keep it in a separate cabinet. Aniline will darken after a period of time, due to oxidation from air. To limit this, you can either make the bottle air-tight, store it under inert gas or add a compatible reducing agent, to scavenge the dissolved oxygen.

When using the aniline for reactions, it's best to purify it first, and this can be done by distilling it under vacuum.

Disposal

Due to aniline's high flash point (70 °C), burning it in not a (good) option, as heating it to achieve the flash point will release lots of unpleasant and highly toxic aniline vapors. You can however, dilute it in a more flammable solvent and burn it in this form. Since some aniline will escape, it's mandatory to do this outside.

Aniline can be destroyed by adding it dropwise in a fresh solution of Fenton's reagent. Since the oxidation will aerosolize a small amount of aniline, this is best done outside. As aniline has a strong and unpleasant smell, do not do this indoors!

Adding water or an acid to aniline will generate a white mist, consisting of a very fine aniline salt, resulted from the reaction of aniline and acid vapors. This will (very slowly) settle on in the room, on various objects, clothes, furniture and will release aniline in contact with a stronger base.

References

Relevant Sciencemadness threads

• OTC aniline?