Aspirin for its health effects for at least 2,400 years. In 1853, chemist Charles Frédéric Gerhardt treated the medicine sodium salicylate with acetyl chloride to produce acetylsalicylic acid for the first time. For the next fifty years, other chemists established the chemical structure and came up with more efficient methods to make it. In 1897, scientists at the Bayer company began studying acetylsalicylic acid as a less-irritating replacement medication for common salicylate medicines. By 1899, Bayer had named it "Aspirin" and sold it around the world. Aspirin's popularity grew over the first half of the twentieth century leading to competition between
Silicotungstic acid Silicotungstic acid Silicotungstic acid (also known as tungstosilicic acid) is the most commonly encountered heteropoly acid. It is a pale yellow solid with the chemical formula H[WSiO]. It is used as a catalyst in the chemical industry. Silicotungstic acid is used to manufacture ethyl acetate by the alkylation of acetic acid by ethylene: It has also been commercialized for the oxidation of ethylene to acetic acid: This route is claimed as a "greener" than methanol carbonylation. The heteropoly acid is dispersed on silica gel at 20-30 wt% to maximize catalytic ability. It has also recently been proposed as a mediator