反应详情

温度

0 °C

2.5 M n-BuLi in hexanes (2.3 mL, 5.77 mmol, 1.5 Eq.) was added dropwise to a stirred solution of diisopropylamine (815 μL, 5.77 mmol, 1.5 Eq.) in anhydrous THF (20 mL) at −78° C. under nitrogen. The reaction was stirred at this temperature for 15 minutes then warmed to 0° C. for 30 minutes. The reaction was cooled to −78° C. and a solution of methyl 3-(1-(2-chlorophenyl)ethoxy)thiophene-2-carboxylate (1.14 g, 3.84 mmol, 1.0 Eq.) in anhydrous THF (10 mL) was added dropwise. After stirring at this temperature for 10 minutes, a solution of 2-isopropoxy-4,4,5,5-tetramethyl[1,3,2]-dioxaborolane (1.78 mL, 5.77 mmol, 1.0 Eq.) in anhydrous THF (10 mL) was added dropwise and stirred at −78° C. for 15 minutes then warmed to ambient temperature for 45 minutes. 1M HCl (30 mL) was added and the mixture extracted with EtOAc (3×40 mL). The combined organic extracts were washed with brine (30 mL), dried (MgSO4) and the solvent removed in vacuo. The residue was recrystalised from cyclohexane to give the sub-title compound as a white solid (837 mg, 1.98 mmol, 51%); 1H NMR (400 MHz, CDCl3) δ 1.38 (12H, s), 1.67 (3H, d), 3.90 (3H, s), 5.80 (1H, quint), 7.18 (1H, s), 7.21-7.7.34 (2H, m), 7.38 (1H, dd), 7.77 (1H, dd).

1. temperatureThe reaction was cooled to −78° C.
2. stirringAfter stirring at this temperature for 10 minutes
3. stirringstirred at −78° C. for 15 minutes
4. temperaturethen warmed to ambient temperature for 45 minutes
5. extractionthe mixture extracted with EtOAc (3×40 mL)
6. washThe combined organic extracts were washed with brine (30 mL)
7. dry with materialdried (MgSO4)
8. customthe solvent removed in vacuo
9. customThe residue was recrystalised from cyclohexane