“…Cinnamic acids are well-known for their presence in various natural products and are important in antioxidant, antifungal, anticarcinogenic, antiviral, and antibacterial activities . While a number of synthetic procedures are known for cinnamic acids, those reported for the synthesis of o -substituted cinnamic acids are scant. , One of the important o -substituted cinnamic acids is o -carboxycinnamic acid, which is widely used as a synthon for the preparation of o -carboxyhydrocinnamic acid, ( E )-methyl-2-methoxycarbonylcinnamates, o -carboxycinnamamides, and methyl 2-carboxy-hydrocinnmates, etc. It should be noted that various indanones and indoles are frequently synthesized from ortho -substituted cinnamic acids. , The known synthetic methods for the latter are based on the oxidation of naphthols with different oxidation reagents, which include 85% aq.…”