To a solution of methyl 6-(1-hydroxy-2-methyl-1-(1-trityl-1H-imidazol-4-yl)propyl)-2-naphthoate (16.4 g) in THF (160 mL) was added methanol (35 mL) and 4N-NaOH (35 mL) at 60° C. The mixture was stirred for 2 h, neutralized with conc.HCl. The mixture was concentrated, diluted with water and extracted with ethyl acetate. The extract was concentrated to give crude mixture of 6-(1-hydroxy-2-methyl-1-(1-trityl-1H-imidazol-4-yl)propyl)-2-naphthoic acid. To a solution of the crude mixture was added isopropylamine (3.95 mL), 1-hydroxybenzotriazole (5.33 g), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (6.67 g) and diisopropylethylamine (6.0 mL) under ice cooling. The mixture was stirred at room temperature for 14 h, diluted with water and extracted with ethyl acetate. The extract was washed with brine, concentrated. The residue was crystallized from ethyl acetate to give the titled compound (16.7 g) as a colorless powder.
