CC(C)([O:4][C:5](=[O:23])[CH2:6][CH2:7][C:8]1[CH:13]=[CH:12][C:11]([C:14]2[N:15]=[N:16][N:17]([C:19]([CH3:22])([CH3:21])[CH3:20])[N:18]=2)=[CH:10][CH:9]=1)C>FC(F)(F)C(O)=O>[CH3:22][C:19]([N:17]1[N:16]=[N:15][C:14]([C:11]2[CH:12]=[CH:13][C:8]([CH2:7][CH2:6][C:5]([OH:23])=[O:4])=[CH:9][CH:10]=2)=[N:18]1)([CH3:20])[CH3:21]5-[4-(3-(1,1-dimethylethoxy)-3-oxopropyl)phenyl]-2-(1,1-dimethylethyl)-2H-tetrazole (1.0 g, 3.7 mmol) was dissolved in trifluoroacetic acid (14 mL) and stirred at room temperature under argon for 12 hours. The mixture was concentrated and then dissolved in water (35 ml). After adding enough sat. NaHCO3 to raise the pH to 8, the solution was washed with diethyl ether (2×10 mL). The aqueous layer was acidified to pH 3 with 1N HCl and the product was collected by suction filtration to give 4-[2-(1,1-dimethylethyl)-2H-tetrazole-5-yl]benzenepropanoic acid (0.7 g, 3.1 mmol) in 84% yield, mp. 88°-90° C.
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