PROCESS FOR THE PREPARATION OF 2-NITROBENZALDEHYDE

摘要

2-NITROBENZALDEHYDE, A VALUABLE CHEMICAL INTERMEDIATE, IS PREPARED THROUGH THE OXIDATION OF AN ALKALI METAL SALT OF 2-NITROPHENYLPYRUVIC ACID WITH POTASSIUM PERMANGANATE IN AN ALKALINE MEDIUM. Advantageously the requisite starting material is prepared directly by the reaction of 2-nitrotoluene and a diester of oxalic acid in the presence of an alcoholate and is then subjected to the oxidation without isolation. In a preferred embodiment the oxidation reaction mixture is acidified to convert the manganese-(IV) oxide to soluble maganese-(II) salts with concurrent conversion of oxalic acid to carbon dioxide. The process is industrially attractive in terms of the high yield, the availability of starting material and the ease of the manipulative steps involved.