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

Participants

Reaction Steps

To the solution of mandelic acid amide in dichloromethane is added N-ethyldiisopropylamine (1.1 equivalents) at RT. Subsequently p-toluene sulfonic acid chloride (1.0 equivalent) is added keeping the temperature below 25° C. The reaction mixture is stirred at RT until a satisfactory conversion is reached and then washed with saturated sodium bicarbonate solution and water. After a solvent switch to ethyl acetate the solution is concentrated, cooled to −2° C. and the precipitate filtered. The crystals are washed with cooled ethyl acetate and dried in vacuo at 40° C.

Provenance & Evidence