反应详情

温度

80 °C

To intermediate 4 (710 mg, 1.81 mmol) in DMF (50 mL) was added the K2CO3 (275 mg, 1.99 mmol) followed by the ethyl 2-bromo-2-methylpropanate (280 μL, 1.91 mmol; Aldrich) and the reaction heated to 80° C. After 18 h, the reaction cooled to rt and the solvent removed in vacuo. The residue treated with water (200 mL), extracted 3×50 mL CH2Cl2, dried over Na2SO4, filtered and the solvent removed under vaccum. The residue was chromatographed (CH2Cl2/MeOH: 99/1). To afford 680 mg (77%) of Intermediate 5 as a clear oil. 1H NMR(CDCl3): δ 7.95 (d, 2H), 7.60 (d, 2H), 7.15 (d, 2H), 6.75 (d, 2H), 6.05 (t, 1H), 4.45 (d, 2H), 4.15 (q, 2H), 2.65 (s, 3H), 1.50 (s, 6H), 1.20 (t, 3H).

1. temperaturethe reaction cooled to rt
2. customthe solvent removed in vacuo
3. additionThe residue treated with water (200 mL)
4. extractionextracted 3×50 mL CH2Cl2
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. customthe solvent removed under vaccum
8. customThe residue was chromatographed (CH2Cl2/MeOH: 99/1)