C(OC(=O)[NH:7][C:8]1[C:17]2[C:12](=[CH:13][CH:14]=[CH:15][CH:16]=2)[C:11]([C:18]2[O:22][CH:21]=[N:20][CH:19]=2)=[CH:10][CH:9]=1)(C)(C)C>FC(F)(F)C(O)=O>[O:22]1[C:18]([C:11]2[C:12]3[C:17](=[CH:16][CH:15]=[CH:14][CH:13]=3)[C:8]([NH2:7])=[CH:9][CH:10]=2)=[CH:19][N:20]=[CH:21]1Compound 503C (1.34 g, 4.3 mmol) was dissolved in trifluoroacetic acid (10 mL) and the resulting mixture was allowed to stand for 1 h at room temperature. After removing the volatiles in vacuo, the residue was co-evaporated from ethyl acetate/heptane (2×50 mL) to remove traces of trifluoroacetic acid. After partitioning the residue between ethyl acetate (100 mL) and 1N NaOH (75 mL), the organic layer was washed with brine (50 mL), dried over magnesium sulfate and concentrated in vacuo to afford 900 mg (99%) of compound 503D as a yellow crystalline solid. HPLC conditions: 95% at 0.92 min (retention time) (Phenomenex 5 micron ODScolumn, 4.6×30 mm, 10%-90% aqueous methanol over 2 min gradient with 0.1% TFA, monitoring at 254 nm.). MS (ES): m/z 211.22 [M+H]+.
Wird geladen…