合成路线1

The condensation of 2-(4-nitrophenyl)ethanol (I) with imidazolidine-2,4-dione (II) by means of PPh3 and DIAD in THF gives 3-[2-(4-nitrophenyl)ethyl]imidazolidine-2,4-dione (III), which is reduced with H2 over Pd/C in ethanol yielding the 4-aminophenyl derivative (IV). The condensation of (IV) with 2-(3-chloropropyl)malonic acid diethyl ester (V) by means of NaNO2 and NaOAc in water affords the hydrazone (VI), which is isomerized and cyclized in refluxing butanol giving the indolecarboxylic ester (VII). The methylation of the free amino group of (VII) with formaldehyde and NaCNBH3 yields the dimethylamino derivative (VIII) (1), which is transesterified with benzyl alcohol and titanium tetraisopropoxide affording the benzyl ester (IX). The debenzylation of (IX) with H2 over Pd/C gives the free acid (X), which is finally converted into the target amide with benzylamine, TBTU and DIPEA in DMF.