反应详情

A solution of 4-bromo-2-methylpyridine (220.0 mg, 1.28 mmol) in 2.0 mL of THF was cooled to -78° C. and tert-butyllithium (164.0 mg, 2.56 mmol, 1.5 ml of a 1.7M solution in pentane) was added to give a red-orange solution. After 30 minutes a solution of ZnCl2 (348.0 mg, 2.56 mmol) in 4.0 mL THF was slowly added via cannula. The resulting solution was warmed to room temperature, stirred for 40 minutes, and transferred via cannula to a solution of ethyl 4-(2,2-dimethyl-4-trifluoromethanesulfonyloxy-(2H)thiochromen-6-yl-ethynyl)-benzoate (Compound 224, 172.0 mg, 0.35 mmol) and tetrakis(triphenylphosphine) palladium(0) (24.0 mg, 0.02 mmol) in 2.0 mL THF. This solution was heated to 50° C. for 2 hours, cooled to room temperature, and the reaction quenched by the addition of saturated aqueous NH4Cl. The solution was extracted with EtOAc and the combined organic layers were washed with H2O and saturated aqueous NaCl before being dried (MgSO4) and concentrated under reduced pressure. The title compound, 109.0 mg (72%) was isolated by column chromatography (5% EtOAc/hexanes) as a pale-yellow solid. 1H NMR (300 MHz, CDCl3) δ: 8.45 (1H, d, J=2.0 Hz), 8.00 (2H, d, J=8.5 Hz), 7.52 (2H, d, J=8.5 Hz), 7.49 (1H, dd, J=2.3, 8.1 Hz), 7.36 (2H, m), 7.20 (1H, d, J=8.1 Hz), 7.16 (1H, d, J=1.5 Hz), 5.86 (1H, s), 4.38 (2H, q, J=7.1 Hz), 2.63 (3H, s), 1.50 (6H, s), 1.40 (3H, t, J=7.1 Hz).

1. customto give a red-orange solution
2. temperatureThis solution was heated to 50° C. for 2 hours
3. temperaturecooled to room temperature
4. customthe reaction quenched by the addition of saturated aqueous NH4Cl
5. extractionThe solution was extracted with EtOAc
6. washthe combined organic layers were washed with H2O and saturated aqueous NaCl
7. dry with materialbefore being dried (MgSO4)
8. concentrationconcentrated under reduced pressure