Dichloromethane → (S)-2-(Methylamino)-2-oxo-1-phenylethyl 4-methylbenzenesulfonate
Reaktionsgleichung
[C:1]([NH2:11])(=[O:10])[CH:2]([C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1)[OH:3].[OH-].[Na+].[C:14]1([CH3:24])[CH:19]=[CH:18][C:17]([S:20](Cl)(=[O:22])=[O:21])=[CH:16][CH:15]=1.Cl[CH2:26]Cl>>[CH3:26][NH:11][C:1]([C@@H:2]([O:3][S:20]([C:17]1[CH:18]=[CH:19][C:14]([CH3:24])=[CH:15][CH:16]=1)(=[O:22])=[O:21])[C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1)=[O:10]Komponenten
5
Versuchsvorschrift
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.