Paul Friedländer

Born Aug. 29, 1857, in Königsberg; died Sept. 4, 1923, in Darmstadt. German organic chemist specializing in the chemistry of dyes.

From 1888 to 1895, Friedländer taught the chemistry of organic dyes at the Technische Hochschule Fridericiana in Karlsruhe. From 1895 to 1911 he was head of the chemistry division at the Technical Museum in Vienna. In 1911 he became a professor at the Technische Hochschule in Darmstadt.

Friedländer synthesized thionaphthene and thioindigo in 1906. In 1909 he derived dibromoindigo and proved that it was the Tyrian purple dye of ancient times. He succeeded in synthesizing a large number of indigoid dyes, as well as nitro, amino, hydroxy, and sulfo derivatives of naphthalene; he also studied flavones and phthaleins. Friedländer compiled five collections of German patents for dyes and intermediate products; the collections were printed under the title Fortschritte der Theerfarbenfabrikation und verwandter Industriezweige (1888–1901).