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Wenker synthesis
The Wenker synthesis is an organic reaction converting a beta amino alcohol to an aziridine with the aid of sulfuric acid.
The original Wenker synthesis of aziridine itself takes place in two steps. In the first step ethanolamine is reacted with sulfuric acid at high temperatures (250 °C) to form the sulfate mono-ester. This salt is then reacted with sodium hydroxide in the second step forming aziridine. The base abstracts an amine proton enabling it to displace the sulfate group. A modification of this reaction involving lower reaction temperatures (140–180 °C) and therefore reduced charring increases the yield of the intermediate.〔''A Modification of Wenker's Method of Preparing Ethyleneimine'' Philip A. Leighton, William A. Perkins, and Melvin L. Renquist J. Am. Chem. Soc.; 1947; 69(6) pp 1540–40. ()〕
The Wenker synthesis protocol using ''trans''-2-aminocyclooctanol, available from reaction of ammonia with the epoxide of cyclooctene, gives a mixture of cyclooctenimine (the Wenker aziridine product) and cyclooctanone (a competing Hofmann elimination product).〔''Chemistry of Ethylenimine. VII. Cycloöctenimine or 9-Azabicyclo()nonane'' D. V. Kashelikar, Paul E. Fanta J. Am. Chem. Soc.; 1960; 82(18); 4927–30. ()〕
==References==
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