quality:correction, structural:summarization, structural:reformatting
Bayer AG is a German multinational pharmaceutical and biotechnology company and is one of the largest pharmaceutical companies and biomedical companies in the world. Headquartered in Leverkusen, Bayer's areas of business include: pharmaceuticals, consumer healthcare products, agricultural chemicals, seeds and biotechnology products. The company is a component of the EURO STOXX 50 stock market index. Bayer was founded in 1863 in Barmen as a partnership between dye salesman Friedrich Bayer (1825–1880) and dyer Friedrich Weskott (1821–1876). The company was established as a dyestuffs producer, but the versatility of aniline chemistry led Bayer to expand its business into other areas. In 1899, Bayer launched the compound acetylsalicylic acid under the trademarked name Aspirin. Aspirin is on the World Health Organization's List of Essential Medicines. In 2021, it was the 34th most commonly prescribed medication in the United States, with more than 17 million prescriptions. In 1904, Bayer received a trademark for the "Bayer Cross" logo, which was subsequently stamped onto each aspirin tablet, creating an iconic product that is still sold by Bayer. Other commonly known products initially commercialized by Bayer include heroin, phenobarbital, polyurethanes, and polycarbonates. In 1925, Bayer merged with five other German companies to form IG Farben, creating the world's largest chemical and pharmaceutical company. The first sulfonamide and the first systemically active antibacterial drug, forerunner of antibiotics, Prontosil, was developed by a research team led by Gerhard Domagk in 1932 or 1933 at the Bayer Laboratories. Following World War II, the Allied Control Council seized IG Farben's assets because of its role in the Nazi war effort and involvement in the Holocaust, including using slave labour from concentration camps and humans for dangerous medical testing, and production of Zyklon B, a chemical used in gas chambers. In 1951, IG Farben was split into its constituent companies, and Bayer was reincorporated as Farbenfabriken Bayer AG. After the war, Bayer re-hired several former nazis to high-level positions, including convicted nazi warcriminals found guilty at the IG Farben Trial like Fritz ter Meer. Bayer played a key role in the Wirtschaftswunder in post-war West Germany, quickly regaining its position as one of the world's largest chemical and pharmaceutical corporations. In 2016, Bayer merged with the American multinational Monsanto in what was the biggest acquisition by a German company to date. However, owing to the massive financial and reputational blows caused by ongoing litigation concerning Monsanto's herbicide Roundup, the deal is considered one of the worst corporate mergers in history. Bayer owns the Bundesliga football club Bayer 04 Leverkusen.