Oxidative cleavage of S-Arylmercaptoacetic acids by pyridinium chlorochromate: Kinetic and correlation analysis

✍ Scribed by S. Kabilan; R. Girija; V. Rajagopal

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 119 KB
• Volume: 31
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/(sici)1097-4601(1999)31:10<683::aid-jck1>3.0.co;2-9

✦ Synopsis

Kinetics of oxidation of 24 S-Arylmercaptoacetic acids (SAMA) by pyridinium chlorochromate (PCC) have been studied in acidmedium. The product of oxidation is the corresponding thiophenol. The rate data of meta-and para-substituted acids have been correlated well with I , R o values and the meta-compounds correlate well with F,R values. The reaction constants are negative and of smaller magnitudes. Further, the ortho-substituted acids show a good correlation with triparametric equation involving Taft's I and R o and charton's steric parameter v. There is no considerable steric contribution to the total orthosubstituent effect. Based on these observations, the mechanism involving the formation of protonated arylsulfinylacetic acid intermediate, followed by an intramolecular rearrangement leading to the product thiophenol has been proposed.