Methanol → Tert-butyl 4-(5-bromo-4-methylthiophen-2-yl)piperidine-1-carboxylate

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Reaction Steps

To Compound 1062 (1.67 g, 5.98 mmol) in a solution of methanol and ethyl acetate (40 mL, 1:1) was added palladium on carbon (1 g, 10%, Degussa type). The reaction was shaken under hydrogen atmosphere at 45 psi on a Parr apparatus for 1 hour, filtered through diatomaceous earth, and concentrated under reduced pressure. The resulting material was dissolved in acetonitrile (30 mL) and treated with N-bromosuccinimide (1.14 g, 6.4 mmol). The reaction mixture was stirred for 30 minutes at room temperature and quenched with a saturated solution of sodium sulfite. The crude product was extracted with EtOAc (2×30 mL) and the combined organics were dried over magnesium sulfate and concentrated under reduced pressure. The residue was purified via silica gel chromatography to provide 1.26 g of tert-butyl 4-(5-bromo-4-methylthiophen-2-yl)piperidine-1-carboxylate Compound 1063) as a pale yellow solid; 1H NMR (300 MHz, CDCl3): δ 6.42 (s, H), 4.20-4.01 (m, 2H), 2.77-2.68 (m, 3H), 2.05 (s, 3H), 1.84 (d, J=12.3 Hz, 2H) and 1.50-1.39 (m, 11H).

Provenance & Evidence