By Bradd Libby

An accidental discovery by teenage student William Perkin produced a purple-colored chemical never before found in nature. It opened the door to synthesizing pharmaceuticals, plastics and many of the other products of our modern world.

When in 1453 the Ottoman ruler Fatih Sultan Mehmed was finished conquering Constantinople so thoroughly that even its name no longer remained intact, let’s just say that Europeans would need to set out around the world to find another route east to get Chinese herbs and spices.

And set out they did, in two great branches.

Some, like da Gama, headed south down around Africa and over to Asia. Others, like Columbus, went west. Of course, those who crossed the Atlantic did not find Asia, but in the lands they did reach they sought to create the products of the Middle Eastern and Asian economy on new soils: silk, cotton and sugar.

There they also discovered many delightful new things previously unknown outside the Americas: potatoes and peanuts, tomatoes and tobacco, cacao and coca …

… and the cinchona tree.

If you are not familiar with the cinchona tree, then you have probably never had malaria, or looked at the official coat of arms of the nation of Peru (Peru being the home of the cinchona tree). By the early 1600s, scientists had discovered that the bark of the cinchona tree could treat malaria, though it wasn’t known until much later what it was in the bark that had medicinal effects.

It turns out that it is the chemical quinine. The first isolation of quinine from cinchona bark is credited to the French chemists Pierre Joseph Pelletier and Joseph Bienaimé Caventou in 1820. Its molecular formula was determined in 1854 by German chemist Adolph Strecker.

A marvelous mistake

The previous year, in 1853, exactly 400 years after Constantinople fell, 15-year-old William Henry Perkin had enrolled in the Royal College of Chemistry (now the Department of Chemistry at Imperial College London) to study under August Wilhelm von Hofmann.

Von Hofmann had some ideas on how to synthesize quinine from aniline, a chemical found in coal tar, which London had loads of in the mid-1800s due to the extensive use of coal gas lighting. He gave the task to his student, Perkin. If successful, humanity would no longer rely on tree bark to get quinine and could make as much of the medicine as needed.

It was an excellent task for a professor to foist on to a student, as aniline is toxic to humans, ignites readily and stinks of rotten fish. During the Easter holiday in 1856, while Perkins was working in his home laboratory, one of his experiments failed marvelously.

Instead of making quinine, he produced a brilliant purple dye which he called aniline purple and was later named mauveine. It was the first-ever synthetic dye, a chemical that does not exist anywhere in nature. And it quickly made young Mr. Perkin famous—and a lot of money.

A convergence of economics

But there was one problem. Aniline was expensive, which meant that Perkin’s purple dye was too.

“When I discovered aniline purple,” Perkin recounted in an 1861 lecture, aniline was “only to be met with in the laboratory; in fact, half-a-pound of aniline was then esteemed quite a treasure.” Fortunately, in 1854, a couple of years before Perkin made his discovery, just as Strecker was determining the molecular formula of quinine, French chemist Antoine Béchamp figured out a way to make aniline from nitrobenzene, another chemical in coal tar, which was much more abundant.

It took a couple of years for Perkin to begin commercial production of both his purple dye and the nitrobenzene-derived aniline to make it, but “Béchamp’s process,” Perkin said in 1861, “is now employed for the preparation of aniline by the ton.” What just a few years prior was “only to be met with in the laboratory,” was now ubiquitous.

This is part of a pattern we have seen many times before: sometimes, making something become widely adopted is simply a matter of making it radically cheaper.

For a couple of years around 1860, Perkin’s purple dye was all the rage in ladies’ fashion from London to Paris and beyond, making him wealthy.

But Perkin wasn’t the only one who saw aniline’s potential. In Germany, the Badische Anilin- und Sodafabrik (Baden Aniline and Soda Factory) or BASF, now the world’s largest chemical company, was established to find uses for Béchamp’s cheap and promising chemical.

In 1869, Perkin found a method to commercially produce the red dye alizarin from aniline, but BASF had patented the same process one day before he did. Synthetic alizarin quickly disrupted the production of natural alizarin from the madder plant. Later, in the 1890s, BASF used aniline to make synthetic indigo, and it quickly disrupted natural indigo production.

To dye for

Aniline’s potential did not stop with dyes. Paracetamol (also called acetaminophen) is based on aniline, as was salvarsan, the first successful chemotherapy agent, and prontosil, the first antibacterial drug. Fentanyl is made from aniline too.

Aniline is also used as an antioxidant in rubber processing and to make herbicides like propanil, which is used to kill weeds that grow around rice. But most aniline today is used to make polyurethane.

Perkin had done more than just produce a plague of purple petticoats. Prior to his discovery, the chemicals doctors and scientists worked with were extracted from nature. People would collect specimens they thought might have some sort of medicinal property or textile dyeing ability, or other useful function, and then they would extract and purify the useful components the best they could.

But mauveine was not known from nature, and to this day it has not been found in any plant, animal or mineral. When Perkin synthesized the first batch, he was holding in his hands all of the mauveine known in the entire universe.

And there is no good reason to believe with high certainty that any exists anywhere else. Mauveine contains 26 carbon atoms (plus some hydrogen and nitrogen). Ask any chemist how long it would take to synthesize every compound that contains 26 carbon atoms (plus as much hydrogen or nitrogen as they want) and they will probably puff out their cheeks and look off into the distance as if you just asked them how much time it would take to walk to Saturn. The correct answer is “essentially infinite.”

What Perkin did by making the first chemical not known in nature was to open the door a crack to the possibility of making anything we could conceive. He did not just discover one molecule—he essentially invented all of them.

From synthetic chemistry, people were able to produce things that are found in nature, like indigo dye and the red dye alizarin, but also things that are not, like paracetamol, prontosil, Propanil, polyurethane and, of course, Perkin’s purple. No longer were scientists limited by the chemicals nature had discovered on her own. In principle, they could make any ones they wanted.

However, it takes a lot of time and hard work to find a way. It took until 1944, about 90 years after Perkin’s experiments, for people to finally synthesize quinine, but since then we have developed other, better treatments for malaria. The chemical structure for mauveine itself—how each of the carbons, nitrogens and hydrogens are connected to each other—was not identified until 1994.

Read more blogs in this series: Pattern of Disruption Part 9