Gerhard Schrader (chemist)

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Paul Gerhard Heinrich Schrader (born February 25, 1903 in Bortfeld , Lower Saxony , † April 10, 1990 in Wuppertal-Cronenberg ) was a German chemist .

life and work

Gerhard Schrader grew up in Bortfeld , today in Wendeburg , and studied chemistry at the Technical University of Braunschweig after finishing school . In 1928 he was awarded a Dr.-Ing. doctorate and went to Bayer AG in the dye research and in 1930 the main laboratory in Leverkusen.

From his work on organic phosphoric acid esters from 1936 on, the dangerous nerve toxins Tabun (1936) and Sarin (1938) emerged. Schrader was tasked with developing insecticides and tried combinations of phosphorus compounds with cyanide. When he first tried sarin precursors, he poisoned himself and was confined to bed for weeks. The follow-up preparation 9/91 had even more dramatic effects on mammals and was no longer considered an insecticide for the company. Instead, they gave it to the military, who examined it in a poison gas development department in the Spandau citadel . The nerve gas was called tabun and Schrader and a colleague received 50,000 Reichsmarks for release. In 1938 he found a nerve poison that was twice as poisonous for monkeys, initially called substance 146 and later sarin, which he handed over to military research in Spandau in 1939.

Schrader developed the first organic insecticide, TEPP , in 1938. In 1944, Schrader's working group succeeded in converting the P = O function of the phosphoric acid ester into a P = S function. These modified thio-phosphoric acid esters are significantly less toxic to mammals and have found or are being sold as insecticides and herbicides. Schrader's group synthesized the insecticide parathion - also known as E 605. Even today, such modified thio-phosphoric acid esters are still used as crop protection agents. Compared to insecticides based on organic chlorine compounds such as DDT and lindane , thio-phosphoric acid esters are readily biodegradable in the soil.

Schrader was held by the Allies for two years after the war in the fortress Kransberg (Taunus) , where he had to write down his research results on organic phosphoric acid esters. In 1949 he and his team were the first to synthesize cyclosarin , another G-warfare agent .

In 1952 Schrader found Trichlorfon (TCP) with colleagues . This substance splits off hydrogen chloride at pH = 5.4, producing dichlorvos (DDVP). For example, cattle with skin bumps from a species of fly were treated with TCP. TCP is only slightly toxic in the intestine and has been used in schistosomiasis for some time since 1960 .

Honors

Gerhard Schrader was awarded the Otto Appel Memorial Coin in 1955 . In 1956 he was awarded the Adolf von Baeyer Memorial Medal by the Society of German Chemists for his outstanding services in the discovery of novel pesticides .

literature

Individual evidence

  1. ^ Sarah Everts The Nazi origins of deadly nerve gases , Chemical and Engineering News, October 17, 2016. The report follows Jonathan Tucker's "War of nerves," Pantheon Books 2006.
  2. ^ Klaus Ruthenberg:  Schrader, Paul Gerhard Heinrich. In: New German Biography (NDB). Volume 23, Duncker & Humblot, Berlin 2007, ISBN 978-3-428-11204-3 , p. 508 ( digitized version ).
  3. ↑ K. Willis, H. Salem, FR Siddell, Article Cyclosarin, in Encyclopedia of Toxicology, 2014, pp. 726-730.

Web links

personal data
SURNAME Schrader, Gerhard
ALTERNATIVE NAMES Schrader, Paul Herhard Heinrich
BRIEF DESCRIPTION German chemist
DATE OF BIRTH February 25, 1903
PLACE OF BIRTH Bortfeld (Wendeburg)
DATE OF DEATH April 10, 1990
Place of death Cronenberg (Wuppertal)