Acetic Acid → 3-Benzyl-3-azabicyclo(3.2.1)octan-8-one

Participants

Reaction Conditions

Reaction Steps

A solution of benzylamine (127.4 g, 1.19 mol) in methanol (125 mL) was added dropwise over 3 h to a refluxing solution of cyclopentanone (100 g, 1.19 mol), paraformaldehyde (107 g, 3.57 mol), and glacial acetic acid (71.4 g, 1.19 mol) in methanol (600 mL) under nitrogen. After 1 h at reflux, the brown mixture was stirred overnight at 25° C. and concentrated in vacuo. The resulting oil was diluted with water (200 mL) and basified with 6 N NaOH (200 mL). The aqueous solution was extracted with dichloromethane (3×400 mL). The combined organic extracts were dried (Na2SO4), and concentrated in vacuo. The residue was chromatographed, eluting with ethyl acetate: dichloromethane (1:35), to afford 47.6 g (19%) of the sub-title compound as a yellow oil.

Provenance & Evidence