N,N-dimethylformamide;methylsulfinylmethane

反应条件: temp:-10.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a pre-cooled (−30° C.) solution of DMF:DMSO (1:1, 200 mL) under nitrogen was added TsCl (76.3 g, 0.4 mol) in small portions over 30 min. NOTE: This reaction is highly exotermic and careful temperature control is essential! The solution was stirred at −10° C. for 10 min, then again taken to −30° C. A solution of cbz-L-serine methyl ester (20.3 g, 0.08 mol, CAS 1676-81-9) in DMF was added dropwise, again with careful temperature control. After stirring for 10 min at −30° C. triethylamine (110 mL, 0.79 mol) was added and the reaction was slowly taken to 0° C. and kept at this temperature for 2 h. The reaction was quenched by addition of ice-cold water. The solution was extracted with 3×EtOAc, then the combined organic layer was washed extensively with brine and water. Drying and evaporation gave product as yellow oil (30 g, 94%). again taken to −30° C was added was slowly taken to 0° C. kept at this temperature for 2 h The reaction was quenched by addition of ice-cold water The solution was extracted with 3×EtOAc the combined organic layer was washed extensively with brine and water Drying evaporation