Zeisel determination
The Zeisel determination or Zeisel test is a chemical test for the presence of esters or ethers in a chemical substance.[1][2][3][4] It is named after the Czech chemist Simon Zeisel (1854–1933). In a qualitative test a sample is first reacted with a mixture of acetic acid and hydrogen iodide in a test tube. The ensuing reaction results in the cleavage of the ether or the ester into an alkyl iodide and respectively an alcohol or an carboxylic acid.
![](../I/m/Zeisel01.png)
By heating this mixture, the gases are allowed to come into contact with a piece of paper higher up the test tube saturated with mercury(II) nitrate. Any alkyl iodide present will give a reaction with the mercury compound to mercury(II) iodide which has a red or yellow color.
The reaction can also be used to determine the number of methoxy (-OCH3) groups,[5] by distilling the iodomethane into a solution of silver nitrate, which precipitates silver iodide. By filtering and weighing this precipitate it is possible to calculate the number of iodine atoms and hence methoxy groups.
Synthetic applications:
![](../I/m/Zeisel02.png)
External links
References
- ↑ S Zeisel. Monatshefte für Chemie 6 (1885) p989. http://www.springerlink.com/content/j6n1272v54q05027/
- ↑ S Zeisel. Monatshefte für Chemie 7 (1886) p406. http://www.springerlink.com/content/w135j20507818364/
- ↑ V Prey. Chemische Berichte 74 (1941) p350.
- ↑ Lange. J Org Chem 27 (1962) p2037.
- ↑ Ziesel Reaction