Microwave assisted chemistry: A rapid and regioselective route for direct ortho-acylation of phenols and naphthols by methanesulfonic acid as catalyst

Direct ortho-acylation of phenols and naphthols with methanesulfonic acid (MSA) as the catalyst has been studied under microwave stimulation. The microwave assisted reaction was environmentally benign in terms of faster reaction, useful conditions and higher yield of the desired products. However, after 3–4 min reaction time at 200–300 Watt, selectivity to over 98% ortho-acylation products was obtained. These reactions have some advantages in competition with other methods such as; short reaction times, high yield and regioselectivity of products, mild reaction conditions and easy workup of the reactions.