[CH3:1][O:2][C:3](=[O:20])[C:4]1[CH:9]=[C:8]([C:10]2[N:11]=[N:12][NH:13][N:14]=2)[N:7]=[C:6]([NH:15][C@H:16]([CH2:18][CH3:19])[CH3:17])[CH:5]=1.F[B-](F)(F)F.[CH3:26][O+](C)C>C(OCC)(=O)C>[CH3:1][O:2][C:3](=[O:20])[C:4]1[CH:9]=[C:8]([C:10]2[N:11]=[N:12][N:13]([CH3:26])[N:14]=2)[N:7]=[C:6]([NH:15][C@H:16]([CH2:18][CH3:19])[CH3:17])[CH:5]=1Treat a solution of (S)-2-sec-butylamino-6-(2H-tetrazol-5-yl)-isonicotinic acid methyl ester (350 mg, 1.26 mmol) in ethyl acetate (8 mL) with trimethyloxonium tetrafluoroborate at room temperature for 3 h. Dilute with ethyl acetate (50 mL) and wash with saturated sodium bicarbonate and saturated aqueous sodium chloride. Dry (sodium sulfate) and concentrate to give the title compound which is used directly in the next step without further purification.
Wird geladen…