George Levitt

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General structural formula of the sulfonylureas
Y = N or CH
Chlorsulfuron

George Levitt (* 1925 in Newburgh (New York) ) is an American chemist who discovered the sulfonylureas (SU) family of herbicides . These are very versatile, so that a selective derivative has been found for practically every crop.

Life

He served in the US Navy during World War II . In 1956, Levitt joined DuPont in the agrochemicals division. In 1957 he synthesized various derivatives of the arylsulfonyl isocyanates, which, however, showed no biological activity. Nevertheless, they were included in DuPont's substance library.

In 1974, an entomologist at DuPont discovered some herbicidal activity in one of Levitt's compounds. Levitt manipulated the structure of the antidiabetic drug tolbutamide and made derivatives of it. In 1975 he found R4321, which showed an excellent effect. In February 1976 he finally discovered chlorsulfuron , which was the first of the sulfonylureas to be commercialized in 1982.

In Germany, the first sulfonylurea was only brought onto the market in 1985 with Metsulfuron-methyl . The application rate to keep a field weed-free fell with the sulfonylureas by a factor of 100 to 1000 to 7–45 g · ha −1 . Before that, up to 2500 g · ha −1 were necessary ( Triallat ).

In 1989 he was awarded the ACS Award for Creative Invention . In 1993 Levitt received the National Medal of Technology

Individual evidence

  1. ↑ A Former Dupont Chemist To Get White House Honor His Herbicides Are Powerful. September 30, 1993
  2. ↑ a b Hans G. Drobny, Martin Schulte, Harry J. Strek: 25 years of sulfonylurea herbicides - a few grams changed the world of chemical weed control . In: Julius Kühn Archive . tape 434 , 2012, p. 21–33 , doi : 10.5073 / jka.2012.434.002 ( PDF ). PDF ( Memento of the original from March 4, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / pub.jki.bund.de
  3. ↑ Gaurab Bhardwaj: From Pioneering Invention to Sustained Innovation: The Story of Sulfonylurea Herbicides . In: Chemical Heritage NewsMagazine . tape 25 , no. 1 , 2007 ( PDF ( Memento of November 18, 2006 in the Internet Archive )). From Pioneering Invention to Sustained Innovation: The Story of Sulfonylurea Herbicides ( Memento of the original of November 18, 2006 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / faculty.babson.edu
  4. ^ DuPont Heritage: 1975. George Levitt
  5. ↑ Field and laboratory studies on the relocation and degradation behavior of selected sulfonylurea herbicides in the soil p. 6
  6. ↑ Michigan State University: GEORGE LEVITT: FATHER OF NON-TOXIC HERBICIDES
personal data
SURNAME Levitt, George
BRIEF DESCRIPTION American chemist
DATE OF BIRTH 1925
PLACE OF BIRTH Newburgh (New York)