Hydrochloric Acid → N-Boc-hexahydro-1H-azepin-4-one

Participants

Reaction Steps

To a solution 1-tert-butyl 4-ethyl 5-oxoazepane-1,4-dicarboxylate (compound 82.1, 19.0 g, 66.6 mmol) in 1,4-dioxane (190 mL) was added drop-wise a solution of sodium hydroxide (4.00 g, 100 mmol) in water (100 mL). The resulting mixture was stirred at room temperature overnight. The pH was then adjusted to 4-5 with hydrogen chloride (aq. 3 M) and the resulting solution was extracted with ethyl acetate (2×50 mL). The combined organic extracts were washed with brine (2×10 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The crude residue was purified by silica gel column chromatography using ethyl acetate/petroleum ether (1:3) as the eluent to furnish 11 g (77%) of the title compound as a yellow oil.

Provenance & Evidence