[CH2:1]([C:5]1[O:9][N:8]=[C:7]([C:10]2[O:14][N:13]=[C:12]([C:15]3[CH:32]=[CH:31][C:18]([CH2:19][N:20]4[CH2:23][CH:22]([C:24]([O:26]C(C)(C)C)=[O:25])[CH2:21]4)=[CH:17][CH:16]=3)[N:11]=2)[C:6]=1[CH2:33][CH2:34][CH3:35])[CH:2]([CH3:4])[CH3:3].[C:36]([OH:42])([C:38]([F:41])([F:40])[F:39])=[O:37]>>[CH2:1]([C:5]1[O:9][N:8]=[C:7]([C:10]2[O:14][N:13]=[C:12]([C:15]3[CH:16]=[CH:17][C:18]([CH2:19][N:20]4[CH2:21][CH:22]([C:24]([OH:26])=[O:25])[CH2:23]4)=[CH:31][CH:32]=3)[N:11]=2)[C:6]=1[CH2:33][CH2:34][CH3:35])[CH:2]([CH3:4])[CH3:3].[C:36]([OH:42])([C:38]([F:41])([F:40])[F:39])=[O:37]A solution of tert-butyl 1-(4-(5-(5-isobutyl-4-propylisoxazol-3-yl)-1,2,4-oxadiazol-3-yl)benzyl)azetidine-3-carboxylate (23 mg, 0.048 mmol) in TFA (0.5 mL) was allowed to stand at rt for 2.5 hr. The volatiles were removed in vacuo and the residue was triturated with Et2O and dried to afford 1-(4-(5-(5-isobutyl-4-propylisoxazol-3-yl)-1,2,4-oxadiazol-3-yl)benzyl)azetidine-3-carboxylic acid, TFA (24 mg, 0.044 mmol, 92% yield) as a light yellow glassy solid. HPLC retention time=3.21 minutes (YMC Combi 4.6×50 mm S-5 ODS column) eluting with 10-90% aqueous methanol+0.2% phosphoric acid over a 4 minute gradient. MS: (M+H)=425.20. 1H NMR (400 MHz, MeOD) δ ppm 1.01 (m, 9H) 1.60-1.71 (m, 2H) 2.14 (m, 1H) 2.77 (m, 4H) 3.62-3.73 (m, 1H) 4.30-4.40 (m, 4H) 4.51 (s, 2H) 7.68 (d, J=7.8 Hz, 2H) 8.24 (d, J=7.8 Hz, 2H).
Wird geladen…