Sodium Sulfate → 1-Propyl-2-{[2-(2-fluoropyrid-6-yl)-1H-imidazol-1-yl]methyl}-5-cyano-1H-benzimidazole

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Reaction Steps

Trimethylaluminum (0.54 mL of 2.0M in toluene, 1.09mmol) is added dropwise to a solution of 3-Amino-4-propylaminobenzonitrile (152 mg; 0.87 mmol) in dichloromethane (10 mL), and the mixture was stirred at room temperature for 1 hr. A solution of [2-(2-Fluoropyridin-6-yl)-imidazol-1-yl]acetic acid methyl ester (102 mg; 0.43 mmol) in dichloromethane (5 mL) is added all at once, and the mixture heated at reflux for 16 hr. The brown solution is cooled to room temperature and treated dropwise with methanol (1 mL) then water (2 mL) and stirred at room temperature for 15 min. Anhydrous sodium sulfate is added until the gel becomes solid, the mixture is diluted with dichloromethane (100 mL) and filtered through celite. The filtrate is concentrated to give a brown oil which is dissolved in acetic acid (7 mL) and heated at 100° for 72 hr. The mixture is cooled to room temperature and concentrated. The residue is dissolved in ethyl acetate (15 mL), washed with saturated aqueous NaHCO3 (1×50 mL), then brine (1×50 mL), dried (MgSO4), and concentrated, and the residue purified by preparative thin layer chromatography to give 1-n-Propyl-2-{[2-(2-fluoropyrid-6-yl)-1H-imidazol-1-yl]methyl}-5-cyano-1H-benzimidazole as a light brown semi-solid (57 mg).

Provenance & Evidence