Hydrochloric Acid → (S)-1-((E)-3-{4-[5-(2-Fluoro-phenoxy)-oxazolo[5,4-d]pyrimidin-2-yl]-phenyl}-acryloyl)-pyrrolidine-2-carboxylic acid tert-butyl ester

Participants

Reaction Steps

140 mg of {(E)-3-{4-[5-(2-fluoro-phenoxy)-oxazolo[5,4-d]pyrimidin-2-yl]-phenyl}-acrylic acid were dissolved in 2 ml of N,N-dimethylformamide, and 98 mg of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, 19 mg of 1-hydroxy-7-azabenzotriazole and 397 μl of N,N-diisopropylethylamine were added, followed by the addition of 49 mg of L-proline tert-butyl ester after 5 min. After 16 h at room temperature, 10 ml of water were added, and the mixture was brought to pH 3 by addition of 2 M aqueous hydrochloric acid and extracted twice with ethyl acetate. The combined organic layers were washed with a saturated sodium hydrogencarbonate solution and brine, dried and concentrated in vacuo. The residue was purified by preparative HPLC. 60 mg of the title compound were obtained.

Provenance & Evidence