Sour milk oxidation

The sour milk oxidation is a name reaction in organic chemistry. It was named after its inventor, the German chemist Walter Sauermilch , who developed it together with Wilhelm Mathes . It describes the synthesis of pyridine carbaldehydes .

To the reaction

2-methylpyridine reacts with oxygen in the presence of a catalyst (V ₂ O ₅ / MoO ₃ ). At a temperature of 350–450 ° C, pyridine-2-carbaldehyde is formed with splitting of water :

In a similar manner, pyridine-4-carbaldehyde is formed from 4-methylpyridine ( 4-picoline ) . The oxidation of 2,6-lutidine from sour milk produces 6-methyl-pyridine-2-carbaldehyde .

Pyridine-4-carbaldehyde

6-methyl-pyridine-2-carbaldehyde

If 3-methylpyridine (β-picoline) is used as the starting material, a mixture of pyridine-3-carbaldehyde, pyridine-4-carbaldehyde and 6-methyl-pyridine-2-carbaldehyde is formed.

Individual evidence

↑ ^a ^b ^c ^d Wilhelm Mathes, Walter Sauermilch, Process for the production of pyridine aldehydes , Patent No. 936871 , German Patent Office, December 1955.

↑ Eberhard Breitmaier, Günther Jung, Organic Chemistry, 7th edition, Thieme, Stuttgart, 2012, page 310, ISBN 978-3-13-541507-9 , doi : 10.1055 / b-002-44908

[Patent-1] Wilhelm Mathes, Walter Sauermilch, Process for the production of pyridine aldehydes , Patent No. 936871 , German Patent Office, December 1955.

[Breitmaier-2] Eberhard Breitmaier, Günther Jung, Organic Chemistry, 7th edition, Thieme, Stuttgart, 2012, page 310, ISBN 978-3-13-541507-9 , doi : 10.1055 / b-002-44908