反应详情

(3-amino-5-methoxycarbonylphenyl)boronic acid (2.66 g, 13.6 mmol), Pd(0) [PPh3]4 (1.57 g, 1.36 mmol), potassium carbonate (15 g, 108 mmol) and 1,2-dibromocyclopentene (12 g, 53 mmol) in toluene-ethanol (1:1 60 mL) were stirred at 90° C., under nitrogen, for 2 hrs. Upon cooling, the reaction mixture was poured into water and extracted with ethyl acetate (40×3 mL). The combined organic layers were dried over MgSO4 and concentrated. Purification was carried out on a Biotage® using isohexane containing a gradient of ethyl acetate (0–20%) to give the required product as yellow solid (3.5 g, 87%). 1H NMR (CDCl3):1.96–2.0 (2H,m), 2.50 (2H,t,J=7.4), 2.67 (2H,t,J=7.4), 3.80 (2H,bs), 3.88 (3H,s), 7.14 (1H,s), 7.28 (1H,s), 7.59 (1H,s). LC/MS[MH+]=296, 298 Rt=3.38.

1. temperatureUpon cooling
2. extractionextracted with ethyl acetate (40×3 mL)
3. dry with materialThe combined organic layers were dried over MgSO4
4. concentrationconcentrated
5. customPurification