Oxidative cleavage of S-arylmercaptoacetic acids by sodium perborate: Kinetic and correlation study

✍ Scribed by S. Kabilan; K. Pandiarajan; K. Krishnasamy; P. Sankar

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 475 KB
• Volume: 27
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.550270504

✦ Synopsis

Kinetics of oxidation of twenty six S-arylmercaptoacetic acids (SAMA) (I) by sodium perborate (PB) have been studied in acid medium. The product of oxidation is the corresponding thiophenol. The rate data of meta-and para-substituted acids have been correlated with DSP equations. While the para-compounds correlate well with PI and o;I values, the meta-compounds correlate well with PI and u; values. The reaction constants are negative and of smaller magnitudes. Further, the ortho-substituted acids show a good correlation with a triparametric equation involving Taft's PI and CT; and Charton's steric parameter v. There is a considerable steric contribution to the total ortho-substituent effect. Based on these observations, mechanism involving the formation of protonated arylsulfinylacetic acid intermediate, followed by an intramolecular rearrangement leading to the product thiophenol has been proposed.