Chitosan: an efficient recyclable catalyst for transamidation of carboxamides with amines under neat conditions
aAcademy of Scientific & Innovative Research, Scale up & Process Engineering Unit, CSIR–Central Salt & Marine Chemicals Research Institute, G.B. Marg, Bhavnagar-364 002, India
Green Chem., 2014, Advance Article
Chitosan-catalyzed transamidation of carboxamides with amines under solvent-free conditions with a broad substrate scope and recyclability of the catalyst, with one-pot synthesis of benzo[d]heterocycles is described.
A novel chitosan-catalyzed transamidation of carboxamides with amines under solvent-free conditions is described. A series of amide derivatives as well as more challenging aryl and alkyl amines with long-chain alkyl substituents could be selectively converted into the corresponding transamidation products, which are frequently found in biologically active compounds and pharmaceuticals. Under similar reaction conditions benzo[d]heterocycles were also obtained via a one-pot synthesis through transamidation and subsequent dehydration. Recyclability of chitosan was demonstrated, with quantitative yields of products obtained without any loss of catalytic activity.