3-[4-(4-Chlorophenyl)-2-(2-methyl-1-imidazolyl)-5-oxazolyl]propyl methanesulfonate (400 mg), diethyl 4-hydroxybenzylphosphonate (365 mg), potassium carbonate (276 mg) and N,N-dimethylformamide (10 ml) was stirred at 100° C. for 4 hours. The reaction mixture was poured into water (100 ml) and extracted with ethyl acetate (100 ml×2). The organic layer was dried over anhydrous magnesium sulfate, and concentrated. The residue was subjected to silica gel column chromatography, and diethyl 4-[3-[4-(4-chlorophenyl)-2-(2-methyl-1-imidazolyl)-5-oxazolyl]propyloxy]benzylphosphonate was obtained as a yellow oil (526 mg, 97%) from an ethyl acetate-eluted fraction.
