Paul Friedländer (29 August 1857 – 4 September 1923) was a German

chemist A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a graduated scientist trained in the study of chemistry, or an officially enrolled student in the field. Chemists study the composition of ...

best known for his research on derivates of

indigo InterGlobe Aviation Limited (d/b/a IndiGo), is an India, Indian airline headquartered in Gurgaon, Haryana, India. It is the largest List of airlines of India, airline in India by passengers carried and fleet size, with a 64.1% domestic market ...

(for example thioindigo) and isolation of

Tyrian purple Tyrian purple ( ''porphúra''; ), also known as royal purple, imperial purple, or imperial dye, is a reddish-purple natural dye. The name Tyrian refers to Tyre, Lebanon, once Phoenicia. It is secreted by several species of predatory sea snails ...

from '' Murex brandaris''.

Life and work

Paul Friedländer was born the son of Ludwig Friedländer in

Königsberg Königsberg (; ; ; ; ; ; , ) is the historic Germany, German and Prussian name of the city now called Kaliningrad, Russia. The city was founded in 1255 on the site of the small Old Prussians, Old Prussian settlement ''Twangste'' by the Teuton ...

in 1857. The chemist Carl Gräbe was a regular guest of his father; thus after finishing the gymnasium, Friedländer studied chemistry in

in the laboratories of Gräbe. Later he studied at

Strasbourg Strasbourg ( , ; ; ) is the Prefectures in France, prefecture and largest city of the Grand Est Regions of France, region of Geography of France, eastern France, in the historic region of Alsace. It is the prefecture of the Bas-Rhin Departmen ...

and

Munich Munich is the capital and most populous city of Bavaria, Germany. As of 30 November 2024, its population was 1,604,384, making it the third-largest city in Germany after Berlin and Hamburg. Munich is the largest city in Germany that is no ...

where he assisted

Adolf von Baeyer Johann Friedrich Wilhelm Adolf von Baeyer (; 31 October 1835 – 20 August 1917) was a German chemist who synthesised indigo dye, indigo and developed a Von Baeyer nomenclature, nomenclature for cyclic compounds (that was subsequently extended a ...

. He received his PhD for the work with Baeyer and completed his habilitation in 1883. He left the well-equipped laboratories of Baeyer in Munich in 1884 to work in the small company K. Oehler in Offenbach. In 1888, he became professor at the

University of Karlsruhe The Karlsruhe Institute of Technology (KIT; ) is both a German public university, public research university in Karlsruhe, Baden-Württemberg, and a research center of the Helmholtz Association. KIT was created in 2009 when the University of Ka ...

. During a visit at his parents' in Königsberg, he got engaged and married Martha Kobligk; they had three daughters. Although he liked staying in Germany, Friedländer accepted a position at the Technologische Gewerbemuseum in

Vienna Vienna ( ; ; ) is the capital city, capital, List of largest cities in Austria, most populous city, and one of Federal states of Austria, nine federal states of Austria. It is Austria's primate city, with just over two million inhabitants. ...

in 1895. During that time, he discovered thioindigo. His research on the color variations in substituted indigoes yielded numerous patents and was applied in industrial production. Friedländer isolated and analyzed the

natural dye Natural dyes are dyes or colorants derived from plants, invertebrates, or minerals. The majority of natural dyes are vegetable dyes from plant sources—roots, berry, berries, Bark (botany), bark, leaf, leaves, and wood—and other biological sourc ...

stuff of

. He was able to obtain 12,000 '' Murex brandaris'' from biologists working at the Mediterranean sea. In a complicated process, he isolated 1.4 g of pure Tyrian purple. Contrary to his expectations, the compound did not contain

sulfur Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...

, but was a

bromine Bromine is a chemical element; it has chemical symbol, symbol Br and atomic number 35. It is a volatile red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour. Its properties are intermediate between th ...

substituted

, which had been already synthesized back in 1903. Friedlander was awarded the Lieben Prize for this discovery. In 1911, Friedländer abandoned his position in Vienna and joined the

Technische Universität Darmstadt The Technische Universität Darmstadt (official English name Technical University of Darmstadt, sometimes also referred to as Darmstadt University of Technology), commonly known as TU Darmstadt, is a research university in the city of Darmsta ...

. The University was not far from the dye factories Chemische Fabrik Kalle, Höchst and Cassella that helped Friedländer in his research on dyes. In 1911, he was awarded the ''Adolf-von-Baeyer-Prize''. During

World War I World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...

, Friedländer worked at the Kaiser Wilhelm Institute for Physical Chemistry and Elektrochemistry together with

Fritz Haber Fritz Jakob Haber (; 9 December 1868 – 29 January 1934) was a German chemist who received the Nobel Prize in Chemistry in 1918 for his invention of the Haber process, a method used in industry to synthesize ammonia from nitrogen gas and hydrog ...

. The poor living standards after the war affected his health, and after a trip in the summer of 1923 from Darmstadt to Biebrich, Friedländer had to stay in a hospital. His health problems gradually deteriorated and on 4 September 1923 he died in Darmstadt. The chemical reaction of

2-aminobenzaldehyde 2-Aminobenzaldehyde is an organic compound with the formula C6H4(NH2)CHO. It is one of three isomers of aminobenzaldehyde. It is a low-melting yellow solid that is soluble in water. Preparation and reactions It is usually prepared by reduction ...

s with

ketone In organic chemistry, a ketone is an organic compound with the structure , where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group (a carbon-oxygen double bond C=O). The simplest ketone is acetone ( ...

s to form

quinoline Quinoline is a heterocyclic aromatic organic compound with the chemical formula C9H7N. It is a colorless hygroscopic liquid with a strong odor. Aged samples, especially if exposed to light, become yellow and later brown. Quinoline is only sl ...

derivatives, which Friedländer discovered in 1882, is today known as the Friedländer synthesis.

References

{{DEFAULTSORT:Friedlander, Paul 1857 births 1923 deaths 19th-century German chemists 20th-century German chemists Scientists from Königsberg Scientists from the Province of Prussia 19th-century German Jews University of Königsberg alumni University of Strasbourg alumni Ludwig Maximilian University of Munich alumni Academic staff of the Karlsruhe Institute of Technology Academic staff of Technische Universität Darmstadt