Benzoyl chloride → ethyl 2-(3-benzoyl-2,5-dimethyl-4-(2-(pyrrolidin-1-ylsulfonyl)benzyl)-1H-pyrrol-1-yl)acetate

関与物質

反応手順

In a small vial charged with ethyl 2-(2,5-dimethyl-3-(2-(pyrrolidin-1-ylsulfonyl)benzyl)-1H-pyrrol-1-yl)acetate (143.7 mg, 0.355 mmol) in DCM (4 mL), at 0° C., was added dropwise a solution of ethylaluminum dichloride (444 μL, 0.444 mmol) in toluene. The reaction mixture turned deep rose color and benzoyl chloride (61.9 μL, 0.533 mmol) was added. The resulting mixture became orange and slowly was allowed to warm to rt. The reaction was stirred 5.25 h and then cooled once again and an additional 800 μL of EtAlCl2 and 150 μL of benzoyl chloride were added. The reaction was once again allowed to warm to room temperature slowly with stirring and stirred an additional 15.25 h at room temperature. The reaction was then quenched by the addition of water and dichloromethane and the water layer was extracted with DCM (3×). The organic layer was dried with MgSO4, and concentrated under vacuum. The crude product was added to a 40 g ISCO silica gel column and purified with a gradient of 0% to 60% EtOAc/hexanes. The product was obtained as a light orange foam (165.2 mg, 0.325 mmol, 91% yield). 1H NMR (CDCl3/400 MHz) δ (ppm) 7.92 (dd, 1H), 7.68 (dd, 2H), 7.46 (t, 1H), 7.38-7.32 (m, 3H), 7.20 (t, 1H), 7.10 (d, 1H), 4.56 (s, 2H), 4.30 (s, 2H), 4.24 (q, 2H), 3.23-3.17 (m, 4H), 2.03 (s, 3H), 1.98 (s, 3H), 1.84-1.78 (m, 4H), 1.29 (t, 3H). MS m/z: 509.40 (M+1).

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