Oxygen → HCID 44591802, compound

Participants

Reaction Steps

In a glove box (O2 content≦2 ppm), a 185-ml stainless steel autoclave was charged with 1.14 mg of [Ir(COD)2]BF4 (0.0023 mmol, S/C 2′000), 1.99 mg of (Ra,S)-DBT-Bn-SIPHOX (0.0025 mmol) and 10 ml of tetrahydrofuran. The formed yellow solution was stirred for 30 min at ambient temperature. Then, 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), 24 ml of methanol, 6 ml of tetrahydrofuran and 0.12 ml of (S)-1-phenylethylamine (0.92 mmol) were added. The autoclave was sealed and the hydrogenation was run at 60° C. for 20 h and subsequently 80° C. for 2 h under 30 bar of hydrogen. After the autoclave was opened and the yellowish solution was rotary evaporated to dryness (50° C./5 mbar) to afford crude (R)-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 98.7% (>99.9% conversion) and an enantiomeric purity of 99.6%.

Provenance & Evidence