Aniline is a toxic organic compound and its main use is in the manufacture of precursors to polyurethane and other chemicals. Similarly to other volatile amines, Aniline has an odor similar to rotten fish. It also ignites easily and burns with a smoky flame.
Aniline was first created in 1826 by Otto Unverdorben who distilled indigo. It was also discovered two other times, but they believed they had discovered something different. It wasn’t until 1843 that they realized they had all discovered the same thing - aniline.
The main use for aniline, and the reason why it is so popular, is due to its use in the dye industry - specifically it’s use as a precursor to indigo, which is the color of blue in blue jeans. The largest use for aniline is in the preparation of methylene dianiline and other related compounds by condensation with formaldehyde.