Bromine → 1-tert-Butyloxycarbonyl-3-bromo-4-oxopiperidine

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Reaction Steps

N-tert-Butoxycarbonyl-4-piperidone (5.67 g, 28.5 mol) is dissolved in a mixture of dry THF (50 ml) and dry ether (50 ml), and thereto is added anhydrous aluminum chloride (57 mg). To the mixture is gradually added dropwise bromine (1.47 ml, 28.5 mmol) at 0° C., and the mixture is allowed to stand at 5° C. for 24 hours. The resulting reaction solution is diluted with ethyl acetate, and the mixture is washed with a saturated aqueous sodium chloride solution, dried over sodium sulfate, and the solvent is evaporated. The resulting residue is crystallized from ether to give N-tert-butoxycarbonyl-3-bromo-4-piperidone (3.40 g, yield; 43%) as pale yellow crystals.

Provenance & Evidence