Chitosan: an efficient recyclable catalyst for transamidation of carboxamides with amines under neat conditions

 

Chitosan: an efficient recyclable catalyst for transamidation of carboxamides with amines under neat conditions

http://pubs.rsc.org/en/Content/ArticleLanding/2014/GC/C4GC01402B?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29

Sadu Nageswara Rao,^a   Darapaneni Chandra Mohan^a and  Subbarayappa Adimurthy*^a  

*Corresponding authors

^aAcademy of Scientific & Innovative Research, Scale up & Process Engineering Unit, CSIR–Central Salt & Marine Chemicals Research Institute, G.B. Marg, Bhavnagar-364 002, India

E-mail: adimurthy@csmcri.org

Green Chem., 2014, Advance Article

DOI: 10.1039/C4GC01402B

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.