反应详情

A solution of 4-ethylbromobenzene (670.9 mg. 3.63 mmol) in 4.0 mL of THF was cooled to −78° C. and tert-butyllithium (464.5 mg. 7.25 mmol, 4.26 mL of a 1.7M solution in pentane) was added to give a yellow solution. After 30 min a solution of ZnCl2 (658.7 mg. 4.83 mmol) in 8.0 mL THF was slowly added via cannula. The resulting solution was warmed to room temperature and transferred via cannula to a solution of ethyl 4-(2,2-dimethyl-4-trifluoromethanesulfonyloxy-(2H)-thiochromen-6-ylethynyl)-benzoate (1.20 g. 2.42 mmol) and tetrakis (triphenylphosphine) palladium(0) (111.7 mg. 0.097 mmol) in 8.0 mL THF. This solution was heated to 50° C. for 1 h, cooled to room temperature, and the reaction quenched by the addition of saturated aqueous NH4Cl. This solution was extracted with EtOAc and the combined organic layers washed with H2O and saturated aqueous NaCl before being dried (MgSO4) and concentrated under reduced pressure. Ethyl 4-[[4-(4-ethylphenyl)-2,2-dimethyl-(2H)-thiochromen-6-yl]-ethynyl]-benzoate was isolated by column chromatography (5% EtOAc/hexanes) as a colorless oil. 1H NMR (300 MHz, CDCl3): δ7.99 (2h, D, j=8.2 Hz), 7.52 (2H, d, J=8.4 Hz), 7.40 (5H, m), 7.35 (2H, m), 5.85 (1H, s), 4.38 (2H, q, J=7.1 Hz), 2.72 (2H, q, J=7.6 Hz), 1.48 (6H, s), 1.40 (3H, t, J=7.1 Hz), 1.30 (3H, t, J=7.6 Hz).

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