Practical Synthesis of 3‐Carboxyindazoles

Abstract A clean, high‐yielding synthetic route to methyl 5‐(bromomethyl)‐1‐tritylindazole 3‐carboxylate 1 was needed. A principal intermediate was 5‐methyl‐3‐carboxyindazole 2. An analysis of a by‐product found after executing Schad's 3‐carboxyindazole synthesis led to undertaking this reaction with an inverse addition in the principal step. This simple modification gave 2 in excellent and reproducible yields.