At -78 °C, tert-butyl N-methylsulfonylcarbamate (2 g, 10 mmol) was dissolved in THF (25 mL) and LDA (2 M solution of THF, 15.4 mL, 30.7 mmol) was added slowly. After addition, the reaction was maintained at -78 °C with stirring for 10 min. Subsequently, diphenylphosphinic chloride (2.42 g, 10.2 mmol) was added dropwise and the reaction was continued at -78 °C for 90 min. Upon completion of the reaction, the reaction was quenched by the addition of water (100 mL) and the reaction mixture was diluted with ethyl acetate (250 mL). The pH of the aqueous layer was adjusted to 5 with 5% aqueous HCl, at which time a white precipitate was produced. The precipitate was collected by filtration and the resulting solid was dried under vacuum to give tert-butyl ((diphenylphosphino)methyl)sulfonylcarbamate (2.9 g, 72% yield) as a final white solid.
