[Cl:1][C:2]1[CH:3]=[C:4]([N:9]2[C:13](=[O:14])[O:12][N:11]=[C:10]2[C:15]2[C:19]([CH2:20][O:21][Si](C(C)C)(C(C)C)C(C)C)=[N:18][O:17][N:16]=2)[CH:5]=[CH:6][C:7]=1[F:8].Cl>CO>[Cl:1][C:2]1[CH:3]=[C:4]([N:9]2[C:13](=[O:14])[O:12][N:11]=[C:10]2[C:15]2[C:19]([CH2:20][OH:21])=[N:18][O:17][N:16]=2)[CH:5]=[CH:6][C:7]=1[F:8]4-(3-Chloro-4-fluorophenyl)-3-(4-[(triisopropylsilyl)oxy]methyl-1,2,5-oxadiazol-3-yl)-1,2,4-oxadiazol-5(4H)-one (1.7 g, 3.7 mmol) was dissolved in anhydrous MeOH (MeOH) (110 mL) followed by addition of 2 M of hydrogen chloride in MeOH (9.2 mL). Reaction was stirred at 70° C. for 4 hrs. After concentration in vacuo the sample was loaded onto 120 g ISCO cartridge eluting with EtOAc/hexane. Fractions were combined and evaporated to yield desired product as an off-white powder. (1.12 g, 97%). 1H NMR (400 MHz, DMSO-d6) δ: 7.96 (dd, J=6.8, 2.3 Hz, 1H), 7.66 (m, 1H), 7.64 (m, 1H), 5.95 (s, 1H), 4.85 (s, 2H); MF═C11H6ClFN4O4; LCMS calculated for C11H7ClFN4O4(M+H)+: m/z=313.014.
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