1,1'-Carbonyldiimidazole → 3-{4-[3-(1-Methyl-1H-benzoimidazol-2-yl)-phenyl]-piperazine-1-carbonyl}-morpholine-4-carboxylic acid tert-butyl ester

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Reaction Steps

To a solution of morpholine-3,4-dicarboxylic acid-4-tert-butyl ester (0.16 g, 0.71 mmol) in acetonitrile (8 mL) was added CDI (0.16 g, 0.71 mmol) and the resulting suspension was stirred at room temperature overnight. 1-Methyl-2-(3-piperazin-1-yl-phenyl)-1H-benzoimidazole dihydrochloride (0.20 g, 0.55 mmol) (obtained as described in method C) and DIPEA (0.19 mL, 1.10 mmol) were added and the resulting solution heated at 65° C. overnight. The reaction was then cooled to room temperature, the solvent removed, the crude product was dissolved with dichloromethane (15 mL) and washed with saturated NaHCO3 solution (2×3 mL) The organic layer was dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography (eluent: gradient from cyclohexane to cyclohexane:EtOAc 2:1) to afford 0.11 g (40%) of the title compound.

Provenance & Evidence