Chen Kao reaction

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Chelate complex of the Chen-Kao reaction based on (1 S , 2 S ) -pseudoephedrine

The Chen-Kao reaction (after Ko Kuei Chen and Chung-Hsi Kao / Cheng-Heng Kao , Madison (Wisconsin) 1926 ) is a chemical method for determining the identity of pseudoephedrine , ephedrine and similar phenylalkylamines .

description

If a solution of pseudoephedrine is mixed with copper sulfate and sodium hydroxide solution , a violet color develops. When shaken with ether, the organic phase turns red and the aqueous phase turns blue. The color is based on the formation of a chelate complex from two ephedrine molecules and a copper ion Cu 2+ :

Chen-Kao reaction of 2-amino-1-phenylpropan-1-ol (cathine) without considering the stereochemistry .

Individual evidence

  1. ↑ K. K. Chen and C. H. Kao: Ephedrine and pseudoephedrine, their isolation, constitution, isomerism, properties, derivatives and synthesis . With a bibliography. In: Journal of the American Pharmaceutical Association . tape 15 , 1926, pp. 625-639 , doi : 10.1002 / jps.3080150804 .
  2. ↑ James Reardon-Anderson : The Study of Change. Chemistry in China, 1840-1949 . In: Studies of the East Asian Institute . 1st edition. Cambridge University Press, Cambridge / New York 1991, ISBN 978-0-521-53325-6 , pp. 224, 235 ( limited preview in Google Book search).
  3. ^ Siegfried Ebel and Hermann J. Roth (eds.): Lexicon of Pharmacy . 1st edition. Georg Thieme Verlag , Stuttgart 1987, ISBN 3-13-672201-9 , p. 134 .