Tetrahydrofuran → Aleglitazar

Participants

Reaction Steps

0.195 g of the above prepared (S)-4-benzyl-3-((2S)-2-methoxy-3-{4-[2-(5-methyl-2-phenyl-oxazol-4-yl)-ethoxy]-benzo[b]thiophen-7-yl}-propionyl)-oxazolidin-2-one (0.32 mmol) was dissolved in 2.25 ml of THF and treated with 0.81 ml of 1N NaOH (2.5 eq.). The reaction mixture was kept at 0° and progress of the hydrolysis followed by TLC. After 1 h the reaction mixture was quenched by pouring onto crashed ice/HCl. Twofold extraction with AcOEt, washing with water and brine, drying over magnesium sulfate, and evaporation of the solvents left a crude product, which was purified by twofold crystallisation from AcOEt/hexane to remove the chiral auxiliary. Thereby, 0.102 g of the title compound was obtained as white solid, mp.118-120°. The enantiomeric excess was judged according to 1H-NMR in the presence of a large excess of optically pure trifluoromethyl-anthryl-ethanol to be >95%. According to chiral HPLC (Chiralpak-AD) it amounts to 99.3%.

Provenance & Evidence