Efficient synthesis of symmetrical bisamides catalyzed by reusable hydroxyapatite

Efficient synthesis of symmetrical bisamides is achieved by hydroxyapatite catalyst. Hydroxyapatite catalyzes the reaction between aldehydes and amides to afford bisamides at reflux conditions in 87–95% yields in acetonitrile medium. The catalyst is readily recovered and reused at least three times without loss in its catalytic activity. This method is noteworthy that, symmetrical bisamides are synthesized by fast, simple, effective, and environmentally benign heterogeneous protocol.