3-(4-Methylbenzenesulfonyl)-3- azabicyclo[3.2.0]heptan-6-one

122080-91-5

122080-99-3

A 1,2-dichloroethane (250 mL) solution of Compound 6 (35 g, 0.10 mol) was slowly added dropwise over 20 minutes to a 1,2-dichloroethane (100 mL) solution of trifluoromethanesulfonic anhydride (58 g, 0.20 mol). Subsequently, a 1,2-dichloroethane (100 mL) solution of colistin (19 g, 0.15 mol) was added slowly over 30 minutes. The reaction mixture was heated to 90 °C and stirred for 2 hours. After completion of the reaction, it was cooled to room temperature and the reaction mixture was concentrated. The residue was hydrolyzed in the two-phase system H2O-CCl4. The organic layer was separated, dried with anhydrous Na2SO4, filtered and the filtrate evaporated to remove the solvent. The residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate=10/1) to afford compound 7 (15 g, 54% yield) as a white solid.1H NMR (400 MHz, CDCl3): δ 2.45 (s, 3H), 2.67-2.72 (m, 1H), 2.85-2.92 (m, 1H), 2.94-3.00 (m, 2H), 3.27-3.35 (m, 1H), 3.59-3.66 (m, 2H), 3.17-3.12 (m, 2H), 3.83-3.86 (d, J=10Hz, 1H), 7.34-7.36 (d, J=8Hz, 2H), 7.69-7.71 (d, J=8.4Hz, 2H); MS calculated values: 265; MS measured value: 266 ([M+H]+).