Cyclization reactions of methylthioacetanilides

The cyclization reactions of methylthioacetanilides mediated by manganese(III) acetate and/or copper(II) acetate are described. Indolinones and indolinediones can be produced effectively via a 5-membered ring cyclization of methylthioacetanilides. The product distributions are highly dependent on the reaction conditions. In most cases, the electronic effect of the substituents on the aryl ring was found to significantly affect the yields of cyclization products. This cyclization reaction proceeded faster with manganese(III) acetate/copper(II) acetate.