Trifluoroacetic acid → 3-Isopropyl-5-(4-(6-(1,2,3,6-tetrahydropyridin-4-yl)benzo[d]thiazol-2-yloxy)piperidin-1-yl)-1,2,4-oxadiazole

To a solution of tert-butyl 4-(2-(1-(3-isopropyl-1,2,4-oxadiazol-5-yl)piperidin-4-yloxy)benzo[d]thiazol-6-yl)-5,6-dihydropyridine-1(2H)-carboxylate (238 mg, 0.453 mmol) in CH2Cl2 (3.5 mL) was added TFA (0.5 mL, 6.7 mmol). The reaction mixture was stirred at rt for 4 h. The reaction mixture was diluted with CH2Cl2 (3 mL) and washed with aq. NaOH (1 N, 10 mL), then brine. The organic layer was dried (Na2SO4), filtered, and concentrated to afford 3-isopropyl-5-(4-(6-(1,2,3,6-tetrahydropyridin-4-yl)benzo[d]thiazol-2-yloxy)piperidin-1-yl)-1,2,4-oxadiazole (190 mg, 0.446 mmol, 99% yield) as a yellow foam. LCMS (m/z)=426 (M+H)+.