Trifluoroacetic acid → 6-(5-{3-chloro-4-[(1-methylethyl)oxy]phenyl}-1,2,4-oxadiazol-3-yl)-2,3,4,5-tetrahydro-1H-3-benzazepine hydrochloride

1,1-Dimethylethyl 6-(5-{3-chloro-4-[(1-methylethyl)oxy]phenyl}-1,2,4-oxadiazol-3-yl)-1,2,4,5-tetrahydro-3H-3-benzazepine-3-carboxylate (Preparation 17) (260 mg, 0.537 mmol) was dissolved in DCM (20 ml) and treated with trifluoroacetic acid (2 ml, 26.0 mmol). The resulting mixture was heated at reflux for 1 hour then evaporated. The resulting residue was partitioned between DCM (10 ml) and 2N NaOH (10 ml). The DCM layer was collected, dried (hydrophobic frit) and evaporated. The free-base was dissolved in 4M HCl in dioxane and evaporated to give the HCl salt, 6-(5-{3-chloro-4-[(1-methylethyl)oxy]phenyl}-1,2,4-oxadiazol-3-yl)-2,3,4,5-tetrahydro-1H-3-benzazepine hydrochloride (225 mg, 0.535 mmol, 100% yield) as an off-white powder. δH (400 MHz, CDCl3) 10.10 (2H, br.s), 8.18 (1H, s), 8.02 (1H, d), 7.82-7.80 (1H, m), 7.33-7.22 (2H, m), 7.05 (1H, d), 5.30 (2H, s), 4.76-4.64 (1H, m), 3.8-3.65 (2H, m), 3.48-3.3 (4H, m), 1.45 (6H, d); MS (ES) C21H2235ClN3O2 requires 383; found 384 [M+H]+.