Trifluoromethanesulfonic anhydride → HCID 86752086, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-nitrobenzyl (7R,8S)-8-[(1R)-1-(tert-butyldimethylsilyloxy)ethyl]-5,9-dioxo-1-azabicyclo[5.2.0]non-2-ene-2-carboxylate (1.5 g, 3.07 mmol) in acetonitrile (15 ml) was added at 0° C. N,N-diisopropylethylamine (1.1 ml, 6.45 mmol). The reaction mixture was cooled at -40° C. and trifluoromethanesulfonic anhydride (0.57 ml; 3.38 mmol) was added. After 5 minutes, further N,N-diisopropylethylamine (1.1 ml, 6.45 mmol) was added to the reaction mixture. Methylmercaptan was then bubbled through the solution at -40° C. during a few seconds. The mixture was allowed to warm to ambient temperature over 1.5 hours. The solvent was evaporated and the residue purified by chromatography on silica gel eluting with ethyl acetate/dichloromethane 3:97 to give 4-nitrobenzyl (7R,8S)-8-[(1R)-1-(tert-butyldimethylsilyloxy)ethyl]5-methylthio-9-oxo-1-azabicyclo[5.2.0]non-2,4-diene-2-carboxylate (776 mg, 47%).

Provenance & Evidence