Zerewitinov's reaction

The Zerewitinow reaction or Zerewitinoff reaction is understood to mean the determination of active hydrogen atoms in a chemical compound.

For this purpose, a methyl magnesium halide, i.e. a Grignard reagent , is reacted with the compound to be examined. It reacts with acidic hydrogen to form a magnesium salt and the corresponding hydrocarbon . The methane produced is determined gas volumetrically . Compounds with an acidic or active H atom can be, for example, water, alcohols , amines or alkynes .

Examples:

• general reaction of methylmagnesium bromide with water:

${\displaystyle \mathrm {CH_{3}{\text{-}}MgBr+H_{2}O\longrightarrow CH_{4}+Mg(OH)Br} }$

• general reaction of methylmagnesium bromide with an alcohol:

${\displaystyle \mathrm {CH_{3}{\text{-}}MgBr+ROH\longrightarrow CH_{4}+Mg(OR)Br} }$

• Reaction of methyl magnesium iodide with propyne , whose hydrogen atom on the sp carbon atom is acidic:

The reaction is named after the Russian chemist Fyodor Wassiljewitsch Zerewitinow (1874–1947).

Individual evidence

1. ↑ ^{a b} Hans Peter Latscha, Uli Kazmaier and Helmut Alfons Klein: Organic Chemistry: Basic Chemistry II . Springer Verlag; 6th completely revised edition. 2008, p. 200, ISBN 978-3540771067 .