Acid Catalysis in the Coupling Reaction of 1-Diazonio-2-naphthol-4-sulfonate with 1-Naphthol

Abstract

Soft Brönsted acids such as phenols, naphthols or hydroxypyridines were found to catalyze the coupling reaction of 1-naphthol with 1-diazonio-2-naphthol-4-sulfonate. In contr ast, a hard acid such as acetic acid was not effective for the reaction. The kinetic data well agreed with the Brönsted equation k=1.3×10²¹ Ka^0.83. Mechanism of the reaction is discussed.