To a chilled (0° C.) solution of ethyl 3,3-bis(4-fluorophenyl)-2-[1-(1-methylethyl)-1H-tetrazol-5-yl]-2-propenoate (0.95 g, 2.39 mmoles) in 20 mL of 1:1 (v/v) mixture of tetrahydrofuran and methanol was added an aqueous solution of LiOH (4.0 mL, 3 Molar) in one single portion. The reaction mixture was stirred at 0° C. for 15 minutes followed by warming up to ambient temperature. Saponification was allowed to proceed at room temperature for four hours forming a very pale clear solution. The crude reaction mixture was diluted with 12 mL of 2M H2SO4 and the product was extracted into diethyl ether (40 mL×2). The organic layers were combined, dried over MgSO4, concentrated under reduced pressure and then vigorously dried under high vacuum (0.01 mmHg) at room temperature for 24 hours to yield the title compound. The propenoic acid was then utilized in the next step without further purification.
