Dichloromethane → 3-Acryloyl-n-methylthio4-(2-chlorophenyl)-2-azetidinone

Participants

Reaction Steps

To a solution of 25 (4.00 g, 11.2 mmol) in 40 ml of CH3CN in an ice-water bath was added ceric ammonium nitrate (18.39 g, 33.54 mmol) in 40 ml of water. The resultant mixture was stirred for 5 min, and 20 ml of water was added. The solution was extracted (3×5 ml) with EtOAc. The combined organic layers were washed with 5% NaHSO3, 5% NaHCO3, and dried over anhydrous MgSO4. The solvent was removed under reduced pressure to yield 2.14 g (76%) of 26 as a crude brown oil. Without further purification, compound 26 (2.00 g, 8.0 mmol) was dissolved in 30 ml of dry CH2Cl2 and N-(methylthio)phthalimide (2.30 g, 11.9 mmol) and 3-5 drops of triethylamine were added. The resultant mixture was refluxed for overnight. The solvent was removed under reduced pressure to yield a brown solid. The brown solid was redissolved in CH2Cl2, and washed with 1% NaOH. The organic layer was dried over anhydrous MgSO4. The solvent was removed under reduced pressure to yield a brown semi-solid, which was purified by column chromatography on silica gel with gradient elution (1:9 then 1:4 EtOAc:hexanes) to yield 2.00 g (88%) of 27 as a white solid. 1H NMR (250 MHz) δ 7.35-7.26 (m, 4H), 6.20 (d, J=5.1 Hz, 1H), 6.06 (dd, J=16.7, 1.9 Hz, 1H), 5.78 (dd, J=16.7, 10.4 Hz, 1H), 5.68 (dd, J=10.4, 1.9 Hz, 1H), 5.54 (d, J=10.4 Hz, 1H), 2.51 (s, 3H). 13C NMR (63 MHz) δ 168.3, 163.4, 156.6, 134.3, 132.6, 129.8, 128.6, 126.6, 126.3, 62.1, 21.9.

Provenance & Evidence