Thio Acid-Mediated Conversion of Azides to Amides – Investigation of 2-Azidotetrahydobenzimidazoles and Derivatives

An investigation of the thio acid-azide coupling reaction to afford amides is reported employing 2-azidotetrahydrobenzimidazoles and the corresponding spiro fused 2-azidoimidazolones. The tetrahydrobenzimidazole derivatives react as expected to produce the analogous amides, whereas the imidazolones result in the formation of the thiohydantoin derivatives. The thiohydantoins appear to result from an addition elimination pathway. (C) 2020 Elsevier Ltd. All rights reserved.