The condensation of 4-(1-benzyloxy-N-methylformamido)butyric acid (I) with o-phenylenediamine (II) and isobutyl chloroformate (III) by means of triethylamine gives N-[3-[N-(2-aminophenyl)carbamoyl]propyl]-N-methylcarbamic acid benzyl ester (IV), which is cyclized by means of p-toluenesulfonic acid in refluxing toluene to the benzimidazole derivative (V). Hydrogenation of (V) with H2 over Pd/C in methanol affords 2-[3-(methylamino)propyl]benzimidazole (VI), which is condensed with the chiral p-toluenesulfonate (VII) by heating at 120 C to give the chiral tetrahydronaphthol (VIII). Finally, this alcohol is esterified with 2-methoxyacetyl chloride and ethyl diisopropylamine in chloroform.

The condensation of 4-(1-benzyloxy-N-methylformamido)butyric acid (I) with o-phenylenediamine (II) and isobutyl chloroformate (III) by means of triethylamine gives N-[3-[N-(2-aminophenyl)carbamoyl]propyl]-N-methylcarbamic acid benzyl ester (IV), which is cyclized by means of p-toluenesulfonic acid in refluxing toluene to the benzimidazole derivative (V). Hydrogenation of (V) with H2 over Pd/C in methanol affords 2-[3-(methylamino)propyl]benzimidazole (VI), which is condensed with the chiral p-toluenesulfonate (VII) by heating at 120 C to give the chiral tetrahydronaphthol (VIII). Finally, this alcohol is esterified with 2-methoxyacetyl chloride and ethyl diisopropylamine in chloroform.