Dry THF (600 ml) containing diisopropylamine (21.3 ml) was cooled to −70° C. and n-butyl lithium (1.6 M; 95.0 ml) was added dropwise. The mixture was stirred for 10 min and ethyl acetate (14.9 ml) was added dropwise. The mixture was stirred at the same temperature for 30 min. A solution of N,N-diisopropyl-6-[(1-trityl-1H-imidazol-4-yl)carbonyl]-2-naphthamide (60.0 g) in dry THF (150 ml) was added dropwise at −70° C. The mixture was stirred at the same temperature for 30 min and the reaction mixture was gradually warmed to −30° C. Water was added to stop the reaction. The organic layer was separated and the aqueous layer was extracted with a THF-toluene (1:1) mixture. The organic layers were combined, washed with saturated brine and dried over magnesium sulfate. The solvent was evaporated to give the title compound quantitatively as a pale yellow oil.
