Trifluoroacetic acid → 5-(2-fluoro-4-(1H-tetrazol-1-yl)phenyl)-2-(piperidin-4-yl)benzo[d]oxazole 2,2,2-trifluoroacetate

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Reaction Steps

Tert-butyl 4-{5-[2-fluoro-4-(1H-tetrazol-1-yl)phenyl]benzo[d]oxazol-2-yl}piperidine-1-carboxylate (120 mg, 0.26 mmol) dissolved in DCM (15 ml) and added Trifluoroacetic acid (0.5 ml). This mixture was stirred at rt for 2 h. DCM removed from the reaction mixture to obtain 5-[2-fluoro-4-(1H-tetrazol-1-yl)phenyl]-2-(piperidin-4-yl)benzo[d]oxazole 2,2,2-trifluoroacetate (150 mg). 5-[2-fluoro-4-(1H-tetrazol-1-yl)phenyl]-2-(piperidin-4-yl)benzo[d]oxazole 2,2,2-trifluoroacetate (70 mg, 0.15 mmol) was dissolved in IPA (10 ml), added DiPEA (0.25 ml, 1.2 mmol) and stirred at rt for 30 mins 2-Chloro-5-ethyl piperidine was added to the above reaction mixture and heated the reaction mixture to 90° C. for overnight. After completion of the reaction, work-up (EtOAc/H2O) followed by purification on combiflash using the gradient mixture of ethyl acetate and petether (1:1) as eluent afforded the titled compound (20 mg) as an off-white solid. M.P.: 188-192° C. 1H-NMR (δ ppm, CDCl3, 400 MHz): 9.03 (s, 1H), 8.20 (s, 2H), 7.88 (s, 1H), 7.68 (t, J 8.2, 1H), 7.65-7.58 (m, 3H), 7.54-7.49 ((m, 1H), 4.80-4.70 (m, 2H), 3.33-3.23 (m, 1H), 3.22 (t, J 14, 2H), 2.48 (q, J 7.6, 2H), 2.30-2.22 (m, 2H), 2.07-1.95 (m, 2H), 1.20 (t, J 7.6, 3H).

Provenance & Evidence