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 (429.1, 19.0 g, 66.6 mmol, 1.00 equiv) in 1,4-dioxane (190 mL) was added dropwise sodium hydroxide (4.00 g, 100 mmol, 1.50 equiv) in water (100 mL). The resulting mixture was stiffed 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 2×50 mL of ethyl acetate. The combined organic layers were washed with 2×10 mL of brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude residue was purified by silica gel chromatography using ethyl acetate/petroleum ether (1:3) as eluent to furnish 11.0 g (77%) of the title compound as a yellow oil.

Provenance & Evidence