Trifluoroacetic acid → (S)-2-Amino-3-[5-(5-chloro-thiophen-2-yl)-isoxazol-3-yl]-propionic acid methyl ester

Beteiligte Stoffe

Reaktionsschritte

Intermediate 1 (3.25 g, 8.51 mmol) in acetonitrile (183 ml) was treated with TFA (90 ml, 2 M in water) and stirred at RT overnight. After complete conversion the mixture was neutralized with sat. aq. NaHCO3-solution, the majority of the acetonitrile was evaporated and the remainder extracted with ethyl acetate. The combined organic phases were washed with brine, dried with MgSO4, filtered and evaporated to dryness. The resulting crude oil (2.5 g) was used in the next steps without further purification.

Herkunft & Nachweise