page_title: Ludwig Knorr
section_title: University of Erlangen
hierarchical_section_title: Ludwig Knorr / University of Erlangen
context_page_description: Ludwig Knorr was a German chemist. Together with Carl Paal, he discovered the Paal–Knorr synthesis, and the Knorr quinoline synthesis and Knorr pyrrole synthesis are also named after him. The synthesis in 1883 of the analgesic drug antipyrine, now called phenazone, was a commercial success. Antipyrine was the first synthetic drug and the most widely used drug until it was replaced by Aspirin in the early 20th century.
context_section_description: In 1882 Knorr received his PhD for a thesis titled Über das Piperyl-Hydrazin. His habilitation followed three years later in 1885 with a thesis titled Über die Bildung von Kohlenstoff-Stickstoff-Ringen durch Ein-wirkung von Amin-und Hydrazinbasen auf Acetessigester und seine Derivate ("On the formation of carbon-nitrogen rings through the action of amine and hydrazine bases on acetoacetate and its derivatives"). In that time, during his search for quinine related compounds, Knorr discovered the unmethylated Phenazone. As another quinine-related compound kairin showed analgesic and antipyretic properties, Knorr and Fisher asked Wilhelm Filehne at the Hoechst company to check the unmethylated and the methylated phenazone for its pharmacological properties. Knorr patented the compound in 1883. Filehne later suggested the names Höchstin or Knorrin for the substance but Knorr telegraphed from his honeymoon that his variant of the name, antipyrine, is not to be changed. (German: Antipyrin bleibt!). In 1885 Knorr married Elisabeth Piloty, the sister of his laboratory colleague Oskar Piloty at the University of Munich.
caption: Antipyrine, now called Phenazone