Syntheses and Ultraviolet Spectra of Aromatic Azo Compounds. II. Azobenzenecarboxylic Acids, Methylazobenzenecarboxylic Acids and their Ethyl Esters

Abstract

Abstract 1) The zinc chloride double salts of ethoxy-carbonylbenzenediazonium chlorides reacted with aryl Grignard reagents to give ethyl azobenzenecarboxylates. This provides a new method for the preparation of these compounds, as has been demonstrated by the preparation of twelve azo compounds, including ten substances not hitherto known. 2) A group of azobenzenecarboxylic acids was prepared by the hydrolysis of the corresponding ethyl esters obtained above ; seven of them are new compounds. 3) The ultraviolet absorption spectra of these esters and free acids were measured.