Hydrochloric Acid → 3-(3-Chloro-4-isopropoxyphenyl)-5-(1,2,3,4-tetrahydroisoquinolin-5-yl)-1,2,4-oxadiazole

To a solution of tert-butyl 5-(3-(3-chloro-4-isopropoxyphenyl)-1,2,4-oxadiazol-5-yl)-3,4-dihydroisoquinoline-2(1H)-carboxylate (0.403 g, 0.858 mmol) in dioxane (17.15 ml) was added a 4N solution of HCl in dioxane (3.86 ml, 15.44 mmol). After about 15 h the reaction mixture was filtered. The resulting solid was partitioned between EtOAc and sat NaHCO3. The organic layer was separated, dried (MgSO4) filtered and concentrated in vacuo to provide 3-(3-chloro-4-isopropoxyphenyl)-5-(1,2,3,4-tetrahydroisoquinolin-5-yl)-1,2,4-oxadiazole (0.230 g, 73%) as a colorless solid. LCMS (Table 1, Method c) Rt=2.00 min, m/z 372 (M+H)+.