Trimethyl orthoformate → [4-(6-{[(1H-imidazol-2-ylmethyl)amino]methyl}-1-propyl-1H-benzimidazol-2-yl)butyl]dipropylamine

Participants

Reaction Conditions

Reaction Steps

The compound (130 mg) obtained in Example 3-6 was dissolved in methanol (3.0 ml) and added with trimethyl orthoformate (0.130 ml) and 2-imidazole carboxaldehyde (37.3 mg) and the whole was stirred for 1 hour. After having been cooled to 0° C., the solution was added with sodium borohydride (21.5 mg) and stirred at room temperature for 3 hours. After completion of the reaction, the solvent was distilled off under reduced pressure and the residue was then dissolved in chloroform. The solution was washed with a 1 mol/l sodium hydroxide aqueous solution and then subjected to extraction with chloroform. The organic layer was washed with a saturated saline solution and then dried with anhydrous sodium sulfate. After filtration, the solvent was distilled off under reduced pressure. Then, the residue was purified through silica gel column chromatography (chloroform/methanol), thereby obtaining the subject compound (64.0 mg) as a pale-yellow oily substance.

Provenance & Evidence