C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.[C:20]([O:23][CH2:24][C:25](=O)[NH:26][C:27]1[CH:32]=[CH:31][C:30]([S:33]([F:38])([F:37])([F:36])([F:35])[F:34])=[CH:29][CH:28]=1)(=[O:22])[CH3:21].C[Si]([N:44]=[N+:45]=[N-:46])(C)C>C1COCC1.CCOC(C)=O>[C:20]([O:23][CH2:24][C:25]1[N:26]([C:27]2[CH:32]=[CH:31][C:30]([S:33]([F:38])([F:37])([F:36])([F:35])[F:34])=[CH:29][CH:28]=2)[N:46]=[N:45][N:44]=1)(=[O:22])[CH3:21]Triphenylphosphine (16.2 g, 61.9 mmol) and diisopropylazodicorboxylate (12.5 g, 61.8 mmol) were added to a solution of 2-oxo-2-{[4-(pentafluoro-λ6-sulfanyl)phenyl]amino}ethyl acetate (Intermediate 42, 8.50 g, 26.2 mmol) in THF (100 mL) at 0° C. and the mixture was stirred for 30 min. Trimethylsilyl azide (7.11 g, 61.7 mmol) was added dropwise at room temperature and the mixture was heated to reflux for 4 hr. The reaction mixture was diluted with EtOAc and washed with ice-water and brine solution, dried over anhydrous Na2SO4, and concentrated under reduced pressure to give the crude product (5.32 g). This was used for the next step without further purification.
Loading…