The title compound was prepared by alkylation of 1-(7-chloro-2,3-dihydro-1,4-benzodioxin-5-yl)piperazine (I) with N-(4-bromobutyl)saccharin (II) in the presence of K2CO3 in methylethylketone (MEK).
The condensation of methyl 3-amino-4-methylbenzoate (I) with methoxy-acetonitrile (II) in the presence of p-toluenesulfonic acid produced the amidine (III). Subsequent oxidative cyclization furnished the benzimidazole (IV). The ester group of (IV) was then saponified with aqueous NaOH to give acid (V). This was activated by treatment with O-benzotriazolyl-N,N,N',N'-tetramethyluronium tetrafluoro-borate (TBTU) in the presence of N-ethyl diisopropylamine, and subsequently coupled with 4-amino-3,5-dichloropyridine (VI) using sodium diethyldihydroaluminate as the catalyst to give the target amide.