Formylation of Amines catalysed by Co3O4 under solvent-free condition

Formyl group is the one of the most useful and versatile protecting group for the protection of amine functionality in organic molecules [1]. Formamides are important intermediates in the preparation of amine derivatives and have been widely used in the synthesis of many fine chemicals and pharmaceutically valuable compounds [2]. A number of other methods have been documented on the N-formylation of amines. Most of them suffer from different drawbacks such as thermal instability, sensitivity to moisture, application of toxic and expensive formylating agents and catalysts, poor atom economy, high temperatures, prolonged reaction times, harsh reaction conditions, formation of undesirable by-products, low yields, while also leading to diformylation and/or lack of regioselectivity and tedious work up. In the recent years, formic acid [3] has been continually accepted as a potent formylating agent owing to its lower toxicity, inexpensivity and easy practical applicability. In summary, we report here that Co3O4 is an efficient and heterogenous system for formylation of amines under solvent free condition with high yields. Simple work up, clean reactions, scale up are some advantages of this method.