Highly Regioselective Iodination of N-Phenylureas with Iodine/Trichloroisocyanuric Acid

An efficient regioselective iodination of N-phenylureas was developed using iodine/trichloroisocyanuric acid in acetonitrile at room temperature. This protocol proved to be effective on a broad range of substituted N-phenylureas, forming the p-iodinated compounds in 65–96% yield under mild and neutral conditions.