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

Participants

Reaction Steps

500 ml of trifluoroacetic acid were added dropwise 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 (a), above] in 700 ml of methylene chloride, whilst ice-cooling, and the mixture was stirred at room temperature for 4 hours. At the end of this time, the reaction mixture was freed from methylene chloride and trifluoroacetic acid by distillation under reduced pressure. The residue was then triturated with a mixture of benzene and a small amount of ethyl acetate, and the crystals which precipitated were collected by filtration. These crystals were recrystallized from a mixture of methanol and ethyl acetate to give 36.9 g of the title compound melting at between 162° C. and 166° C.

Provenance & Evidence