反应详情

A flame-dried flask was charged with the 5-bromo-2-nitroaniline (2, 300 mg, 1.38 mmol) (scheme 1, Example 1), phenylacetylene (155 mg, 1.52 mmol) and ethyl acetate (13.8 mL). The solution was degassed under vacuum and put under N2 atmosphere. Then, dichlorobis(triphenylphosphine)palladium (48 mg, 0.069 mmol) and copper iodide (26 mg, 0.138 mmol) were added. The yellow solution was degassed again (3 cycles) N,N-diisopropylamine (231 μl, 1.68 mmol) was added and the solution rapidly turned dark. It was degassed twice again and allowed to stir under N2 atmosphere at r.t. over 16 h. Then it was passed through celite and the filtrate was successively washed with dilute aqueous ammonia (NH4OH), saturated NaHCO3, saturated NH4Cl, brine, dried over MgSO4, filtered and concentrated. The resulting dark solid was purified by flash chromatography on silica gel using EtOAc/hexanes as the eluent with increasing polarity (10:90 to 15:85) affording the title compound 124 (242 mg, 74% yield) as a deep yellow solid. 1H NMR: (400 MHz, CD3OD) δ(ppm): 8.04 (dd, J=8.8, 0.4 Hz, 1H), 7.54-7.51 (m, 2H), 7.40-7.37 (m, 3H), 7.11 (dd, J=1.8, 0.4 Hz, 1H), 6.73 (dd, J=8.8, 1.8 Hz, 1H). LRMS: (m/z): 239.3 (MH+).

1. customThe solution was degassed under vacuum
2. additionwas added
3. customIt was degassed twice again
4. washthe filtrate was successively washed with dilute aqueous ammonia (NH4OH), saturated NaHCO3, saturated NH4Cl, brine
5. dry with materialdried over MgSO4
6. filtrationfiltered
7. concentrationconcentrated
8. customThe resulting dark solid was purified by flash chromatography on silica gel
9. temperaturewith increasing polarity (10:90 to 15:85)