Mechanistic studies in strong acids. 15. 4-[(3, 4-Dimethoxyphenyl) azo] pyridine: two different pathways in the acid hydrolysis of the two methoxy groups

RA Cox, I Onyido, E Buncel

Index: Cox, Robin A.; Onyido, Ikenna; Buncel, Erwin Journal of the American Chemical Society, 1992 , vol. 114, # 4 p. 1358 - 1363

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Citation Number: 30

Abstract

Abstract: The kinetics of hydrolysis of the two methoxy functions in the title compound 1 have been determined as a function of sulfuric acid concentration. Basicity constants for azo group protonation have been evaluated for 1 and several other (pheny1azo) pyridines. The 4-OMe group in 1 hydrolyzes very readily in aqueous H2S04 at 25'C (half-life, seconds to minutes); the 3-OMe group also hydrolyzes, but more slowly (half-life, hours to days). The ...