Acetic Anhydride → N-(3-benzoyl-5-bromo-thiophen-2-yl) acetamide

Beteiligte Stoffe

Reaktionsschritte

To a stirred solution of 1.00 g (4.92 mmol) of (2-amino-thiophen-3-yl)-phenyl-methanone (the preparation of which is described in example 20) in 20 ml CFCl2 at 0° C. was added 0.92 g (5.18 mmol) NBS (N-bromo succinimide) in one portion. After 10 minutes, 4.65 ml (49.2 mmol) of acetic anhydride, 0.68 ml (4.92 mmol) of Et3N and 0.30 g (2.45 mmol) of DMAP were added. Stirring was continued at RT for 2 hours, the mixture was poured onto water and extracted three times with CH2Cl2. The combined organic phases were dried over sodium sulfate and concentrated in vacuo. Flash chromatography (heptane/CH2Cl2 1:1) afforded 0.85 g (53%) N-(3-benzoyl-5-bromo-thiophen-2-yl)-acetamide as a light brown solid. ES-MS m/e (%): 324, 326 (M+H+, 100).

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