Introducing the Concept of Green Synthesis in the Undergraduate Laboratory: Two-Step Synthesis of 4-Bromoacetanilide from Aniline

Incorporation of green chemistry techniques in undergraduate (UG) laboratories has a great demand. The challenge is to select and modify the known fundamental reactions in a greener way to implement into UG laboratories. A practical, two-step synthesis of 4-bromoacetanilide from aniline through a greener approach is described. Design of the synthetic route is based on the fundamental concepts of green chemistry. It can be adapted in most of the UG laboratories, including those with limited facilities. In the first step, aniline is converted to acetanilide using Zn dust/Fe powder–acetic acid instead of conventional acetic anhydride. In the second step, acetanilide is brominated using ceric ammonium nitrate–KBr combination in ethanolic–aqueous medium instead of bromine. The overall concept of modification could be useful to teach students about the concept of green chemistry, functional group protection, aromatic electrophilic substitution, and laboratory techniques such as reaction setup, isolation, purification, and product analysis.