Oxygen → Aleglitazar

Participants

Reaction Steps

In a glove box (O2 content≦2 ppm), a 185-ml stainless steel autoclave was charged with 2.00 g of (Z)-2-methoxy-3-{4-[2-(5-methyl-2-phenyl-oxazol-4-yl)-ethoxy]-benzo[b]thiophen-7-yl}-acrylic acid (4.59 mmol), 1.80 mg of [Ir((Sa,R)-DBT-Bn-SIPHOX)(COD)]BF4 (0.0015 mmol, S/C 3,000), 24 ml of methanol, 16 ml of tetrahydrofuran and 0.12 ml of (S)-1-phenylethylamine (0.92 mmol). The autoclave was sealed and the hydrogenation was run at 60° C. for 20 h and subsequently 80° C. for 2 h under 60 bar of hydrogen. After the autoclave was opened and the yellowish solution was rotary evaporated to dryness (50° C./5 mbar) to afford crude (S)-2-methoxy-3-{4-[2-(5-methyl-2-phenyl-oxazol-4-yl)-ethoxy]-benzo[b]thiophen-7-yl}-propionic acid (Acid I) as a white solid with a chemical purity of 98.3% (99.4% conversion) and an enantiomeric purity of 99.7%.

Provenance & Evidence