Dichloromethane → (S)-2-(Methylamino)-2-oxo-1-phenylethyl 4-methylbenzenesulfonate

Participants

Reaction Steps

Alternatively, to the solution of mandelic acid amide in dichloromethane is added 50% aqueous caustic soda at RT. Subsequently p-toluene sulfonic acid chloride (1.0 equivalent) is added as a solution in dichloromethane keeping the temperature below 25° C. The biphasic reaction mixture is stirred at RT until a satisfactory conversion is reached, phases are separated, the aqueous phase is extracted once with dichloromethane and then the combined organic phases are washed with water. After a solvent switch to toluene the solution is concentrated, cooled to 5° C. and the precipitate filtered. The crystals are washed with cooled toluene and dried in vacuo at 40° C.

Provenance & Evidence