Acetonitrile → 4-(6-Bromo-benzothiazol-2-yloxy)-piperidine-1-carboxylic acid tert-butyl ester

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Reaction Steps

To a solution of tert-butyl 4-hydroxypiperidine-1-carboxylate (7.02 g, 34.9 mmol) in THF (67.1 ml) at 0° C. was added NaH (0.915 g, 95%, 36.2 mmol). Upon completion of addition, the reaction mixture was warmed to rt, where it stirred for 30 minutes. A solution of 6-bromo-2-chlorobenzo[d]thiazole (6.67 g, 26.8 mmol) in THF (30 mL) was then added and the resulting mixture was heated to 50° C., where it stirred overnight. At the conclusion of this period, the solvent was removed under reduced pressure to yield a residue. CH3CN (167 mL) was added to the residue, and the resulting mixture was stirred for 20 min. After this time, H2O (233 mL) was added, and the resulting mixture was stirred at rt for 10 min. The resulting precipitate was collected by filtration. The resulting solid was rinsed with cool CH3CN—H2O (3×20 mL, 1:2, v/v) and then dried in vacuum to afford Compound 1A as a white solid (10.5 g, 25.3 mmol, 94% yield. HPLC purity is 100%). 1H NMR (500 MHz, chloroform-d) δ ppm 7.77 (d, J=1.9 Hz, 1H), 7.49-7.54 (m, 1H), 7.44-7.49 (m, 1H), 5.35 (ddd, J=7.6, 4.1, 3.9 Hz, 1H), 3.68-3.82 (m, 2H), 3.31-3.43 (m, 2H), 2.01-2.15 (m, 2H), 1.88 (dddd, J=12.6, 8.4, 4.1, 3.9 Hz, 2H), 1.48 (s, 9H).

Provenance & Evidence