合成路线1

The reaction of 3-benzyloxy-2-nitrotoluene (I) with diethyl oxalate and potassium ethoxide yields the potassium salt (II), which on reduction with iron in acetic acid atfords ethyl 7-benzyloxyindole-2-carboxylate (III). After hydrolysis of (III), 7-benzyloxyindole-2 carboxylic acid (IV) is formed, which by treatment with methanolic HCl is converted to methyl 7-benzyloxyindole-2-carboxylate (V). Debenzylation of (V) with H2 over Pd/C affords methyl 7-hydroxyindole-2-carboxylate (VI). Reaction of (VI) with tert-butylaminoacetonitrile hydrochloride in the presence of AlCl3/HCl and catalytic hdrogenation of the resulting aminoketone hydrochloride (VII) over Pd/C gives ZK-90055.