Efficient Synthesis of 2‐Aryl‐4H‐Benzo[d][1,3]oxazin‐4‐ones by Copper‐Catalyzed Decarboxylation of α‐Keto Acids with Anthranilic Acids

An efficient and facile one‐pot approach to the 2‐aryl‐4H‐benzo[d][1,3]oxazin‐4‐ones using the commercially available anthranilic acids and α‐keto acids as start materials, and catalyzed by inexpensive CuCl. With this strategy, a broad substrate concerning anthranilic acids and α‐keto acids also worked well, affording the desired products in good yields.