Trifluoroacetic acid → 5-{4-[2(R)-Aminopropoxy]benzyl}thiazolidine-2,4-dione trifluoroacetate

Participants

Reaction Steps

500 ml of trifluoroacetic acid were added dropwise, whilst ice-cooling, to a solution of 85.5 g of 5-{4-[2(R)-t-butoxycarbonylaminopropoxy]benzyl}-3-triphenylmethylthiazolidine-2,4-dione [prepared as described in step (e) above] in 700 ml of methylene chloride, and the resulting mixture was stirred at room temperature for 4 hours. At the end of this time, the reaction mixture was freed from the methylene chloride solvent and the trifluoroacetic acid by distillation under reduced pressure, and a mixture of benzene and a small amount of ethyl acetate was added to the residue. The crystals which precipitated were collected by filtration and were recrystallized from a mixture of methanol and ethyl acetate, to give the title compound as crystals, melting at 162°166° C. [α]D23 -13.0° (c=0.885, methanol)

Provenance & Evidence