合成路线1

Sulfonylation of anthranilic acid (I) with p-toluenesulfonyl chloride under Schotten-Baumann conditions furnishes N-tosyl anthranilic acid (II). After conversion of acid (II) to the corresponding acid chloride (III), Friedel-Crafts condensation with benzene in the presence of AlCl3 leads to the benzophenone (IV). The N-tosyl group of (IV) is then removed upon heating with concentrated sulfuric acid to provide 2-aminobenzophenone (V). Acylation of amine (V) with 4-(aminosulfonyl)benzoyl chloride (VI) yields amide (VII). This is finally cyclized to the target indole compound under McMurry conditions employing an in situ generated low valent titanium reagent.