合成路线1

Formylation of methyl 4-hydroxyphenylacetate (I) by reaction with MgCl2 and formaldehyde in acetonitrile yields aldehyde (II), which is then brominated by means of NBS in DMF to provide bromo derivative (III). Treatment of (III) with methoxyethoxymethyl chloride and DIEA furnishes O-protected derivative (IV), which is then subjected to Suzuki reaction with boronic acid (V) catalyzed by Pd(PPh3)4 in refluxing toluene in the presence of Na2CO3 to afford biphenyl (VI). Treatment of (VI) with dimethyl-1-diazo-2-oxopropylphosphonate (VII) in MeOH in the presence of K2CO3 furnishes alkyne (VIII), which is then coupled with the iodo-benzonitrile (IX) by means of catalytic Pd(PPh3)2Cl2, CuI and Et3N in acetonitrile to provide indole (X). Saponification of the methyl ester group of (X) with NaOH in THF, followed by hydrolysis with HCl in EtOH, gives carboxylic acid (XI), which is finally converted into the desired product by transformation of the nitrile moiety into an amidine via standard Pinner/aminolysis conditions with NH3 in EtOH followed by treatment with refluxing HCl.