(Diethylamino)sulfur trifluoride → 4-Fluoro-4-[4-(4-methanesulfonyl-phenoxymethyl)-thiazol-2-yl]-piperidine-1-carboxylic acid tert-butyl ester

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Reaction Steps

To a solution of 4-hydroxy-4-[4-(4-methanesulfonyl-phenoxymethyl)-thiazol-2-yl]-piperidine-1-carboxylic acid tert-butyl ester (Example 86, 5.29 g, 11.3 mmol) in CH2Cl2 (100 mL) at 0° C. was added DAST (1.8 mL, 1.2 eq.). The reaction mixture was stirred for 30 minutes before it was quenched by addition of saturated NaHCO3 solution (20 mL). The organic phase was separated and dried over Na2SO4. After removal of the solvent, the crude product was purified on silica gel (EtOAc:hexanes=2:3) to afford the desired product as a white solid. 1H NMR (CDCl3): δ 7.86 (2H, d, J=9.2 Hz), 7.35 (1H, s), 7.10 (2 H, d, J=9.2 Hz), 5.22 (2H, s), 4.08 (2H, br), 3.19 (2H, br), 3.02 (3H, s), 2.05˜2.32 (4 H, m), 1.46 (9H, s).

Provenance & Evidence