Patents

The invention relates to a process for the preparation of (l-alkylindol-3-ylmethyl) benzoic acid derivatives, in particular, Zafirlukast and analogs thereof. Further, this process is based on protection group free and C-H bond activation strategy involving all step catalytic transformation sequence and comprises the following steps: Sonogashira coupling, indole formation by Sp3C-H  activation, reductive hydrogenation and amidation.