Ludwig Knorr (1859-1921)

German chemist, a student of Emil Fischer and professor in Jena. In 1883, while looking for quinine derivatives, he synthesized antipyrine (phenazone), one of the first synthetic drugs against pain and fever, which was an enormous commercial success.

He described the pyrrole synthesis that bears his name, from α-aminoketones and β-keto esters, and the Paal–Knorr synthesis, and studied keto–enol tautomerism: he managed to isolate the keto and enol forms of some compounds separately.

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