Kinetics of oxidation of some meta- and para-substituted phenyl methyl sulfoxides by chloramine-T in buffered ethanol–water

✍ Scribed by K. Ganapathy; P. Jayagandhi

• Publisher: John Wiley and Sons
• Year: 1983
• Tongue: English
• Weight: 375 KB
• Volume: 15
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.550150204

✦ Synopsis

The kinetics of oxidation of methyl phenyl sulfoxide by chloramine-T (CAT) has been studied in buffered ethanol-water (1:l v/v) of pH 7.0. The reaction was found to follow no simple-order kinetics. A possible mechanism is suggested involving three rate-controlling steps: (1) the reaction between RNHCl (R = C H ~C ~H ~S O Z ) and the sulfoxide, (2) the disproportionation of RNHC1, and (3) the reaction between RNC12 and the sulfoxide. A mixed-order rate law is derived as rate/

The rate law is found to be obeyed for the meta-and para-substituted phenyl methyl sulfoxides also. The p value is obtained using Hammett's u constants. The p values obtained for the attack of both RNHCl and RNC12 with the sulfoxides are almost the same, showing that both are converting the sulfoxide to the same intermediate. A chlorinium ion transfer is suggested.