The condensation of methyl 5-methoxy-2-methylindole-3-acetate (I) with p-nitrobenzoyl chloride (II) by means of NaH in toluene gives methyl 1-(p-nItrobenzoyl)-5-methoxy-2-methylindole-3-acetate (III), which is hydrolyzed with p-toluenesulfonic acid in refluxing acetic acid yielding the corresponding free acid (IV). The reduction of (IV) with H2 over Pd/C in methanol affords 1-(p-aminobenzoyl)-5-methoxy-2-methyl indole-3-acetic acid (V) , which is finally treated with NaNO2 and HCl in acetic acid, and with NaN3 in water.

The condensation of methyl 5-methoxy-2-methylindole-3-acetate (I) with p-nitrobenzoyl chloride (II) by means of NaH in toluene gives methyl 1-(p-nItrobenzoyl)-5-methoxy-2-methylindole-3-acetate (III), which is hydrolyzed with p-toluenesulfonic acid in refluxing acetic acid yielding the corresponding free acid (IV). The reduction of (IV) with H2 over Pd/C in methanol affords 1-(p-aminobenzoyl)-5-methoxy-2-methyl indole-3-acetic acid (V) , which is finally treated with NaNO2 and HCl in acetic acid, and with NaN3 in water.

The condensation of methyl 5-methoxy-2-methylindole-3-acetate (I) with p-nitrobenzoyl chloride (II) by means of NaH in toluene gives methyl 1-(p-nItrobenzoyl)-5-methoxy-2-methylindole-3-acetate (III), which is hydrolyzed with p-toluenesulfonic acid in refluxing acetic acid yielding the corresponding free acid (IV). The reduction of (IV) with H2 over Pd/C in methanol affords 1-(p-aminobenzoyl)-5-methoxy-2-methyl indole-3-acetic acid (V) , which is finally treated with NaNO2 and HCl in acetic acid, and with NaN3 in water.