Trifluoroacetic acid → (2S)-2-amino-3-methyl-butyric acid [11beta,17,21-trihydroxy-3,20-dioxo-pregn-4-en-21-yl] ester trifluoroacetate

Beteiligte Stoffe

Reaktionsschritte

500 mg (0.89 mmol) of (2S)-2-((1,1-dimethylethoxycarbonyl) -amino)-3-methyl-butyric acid [11β,17,21-trihydroxy-3,20-dioxo -pregn-4-en-21-yl] ester (Example 27) is mixed with 1 ml of trifluoroacetic acid and stirred for 10 minutes at room temperature. Then, the trifluoroacetic acid is evaporated in a vacuum. The residue is mixed with stirring with a little diethyl ether, the white precipitate that is produced is suctioned off and dried. 385 mg (76%) of (2S)-2-amino-3-methyl-butyric acid [11β,17,21-trihydroxy-3,20-dioxo-pregn-4-en-21-yl] ester trifluoroacetate is obtained.

Herkunft & Nachweise