1-Benzyl-3-oxoazepane

765940-56-5

146407-32-1

The general procedure for the synthesis of 1-benzyl-azepan-3-one from the compound (CAS: 765940-56-5) is as follows: potassium tert-butoxide (336 mg) was suspended in toluene (2.5 mL) and heated under reflux conditions for 10 min. Subsequently, 5-(benzyl-ethoxycarbonylmethyl-amino)-pentanoic acid (695 mg) dissolved in toluene (1 mL) was slowly added to the suspension, and the addition process lasted for 5 hours, after which the reaction was continued at reflux. Upon completion of the reaction, it was cooled to room temperature and acidified by the addition of 25% hydrochloric acid (1 mL). The organic phase was separated and washed with 25% hydrochloric acid (4 x 1 mL). The aqueous hydrochloric acid phase was combined and heated under reflux conditions for 5 hours. After cooling to room temperature, the pH was adjusted to 11 with 2N sodium hydroxide solution to make the solution basic, followed by extraction with ethyl acetate. The organic phases were combined, dried with sodium sulfate and the solvent was evaporated. The resulting residue was purified by silica gel column chromatography (eluent: ethyl acetate/heptane, 1:5) to afford the target product 1-benzyl-azepan-3-one (197 mg) in 45% yield. Ref: Bull. Chem. Soc. Jpn. 1956, 29, 631-632; DE2206385.