N-Boc-hexahydro-1H-azepin-4-one

141642-82-2

188975-88-4

General procedure for the synthesis of tert-butyl 4-oxoazepane-1-carboxylate from ethyl 1-Boc-5-oxoazepane-4-carboxylate: to a solution of 1-tert-butyl 5-oxoazepane-1,4-dicarboxylate (Compound 82.1, 19.0 g, 66.6 mmol) of 1,4-dioxane (190 mL) was added sodium hydroxide (4.00 g) dropwise , 100 mmol) to a solution of water (100 mL). The reaction mixture was stirred at room temperature overnight. Upon completion of the reaction, the pH was adjusted to 4-5 with 3M aqueous hydrochloric acid solution and extracted with ethyl acetate (2 x 50 mL). The organic phases were combined, washed with brine (2 × 10 mL), dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography using ethyl acetate/petroleum ether (1:3) as eluent to afford tert-butyl 4-oxoazepane-1-carboxylate (11 g, 77%) as a yellow oil.