O[CH2:2][C:3]1[CH:8]=[CH:7][C:6]([C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][C:10]=2[NH:15][C:16]([N:18]([CH3:20])[CH3:19])=[O:17])=[CH:5][CH:4]=1.C[Si]([Br:25])(C)C>C(Cl)Cl>[Br:25][CH2:2][C:3]1[CH:8]=[CH:7][C:6]([C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][C:10]=2[NH:15][C:16]([N:18]([CH3:20])[CH3:19])=[O:17])=[CH:5][CH:4]=1A solution of the intermediate obtained in Step B in 4 mL of methylene chloride was treated with 0.16 mL (1.21 mmol) of trimethylsilylbromide. The reaction mixture was stirred at room temperature for 18 hours. The reaction mixture was diluted with methylene chloride then washed with aqueous saturated sodium chloride (2×). The organic layer was dried over magnesium sulfate, filtered and evaporated under vacuum to yield 133 mg of crude product. 1H NMR (400 Hz, CDCl3): δ 2.78 (s, 6H), 4.5 (s, 2H), 6.4 (br s, 1H), 7.08 (t, 1H), 7.16 (dd, 1H), 7.34 (m, 4H), 7.49 (d, 1H), 8.10 (d, 1H).
Wird geladen…