反应详情

A 100-mL single-neck round-bottomed flask equipped with a magnetic stirrer was charged with 26 (1.19 g, 3.40 mmol) and 4M hydrogen chloride in 1,4-dioxane (15.0 mL, 60 mmol), and the mixture was stirred at room temperature for 4 h. After this time, the reaction mixture was concentrated under reduced pressure, and the resulting residue was partitioned between 10% aqueous potassium carbonate (100 mL) and methylene chloride (75 mL). The layers were separated, and the aqueous phase was extracted with methylene chloride (2×75 mL). The combined organic extracts were dried over sodium sulfate, filtered and concentrated under reduced pressure to afford 27 in 81% yield (878 mg) as an orange solid: mp 70-71° C.; 1H NMR (500 MHz, DMSO-d6) δ 7.02 (d, 2H, J=7.5 Hz), 6.49 (d, 2H, J=7.5 Hz), 5.07 (bs, 2H), 4.07-3.97 (m, 3H), 2.81 (septet, 1H, J=6.5 Hz), 1.99 (s, 3H), 1.11 (t, 3H, J=7.0 Hz), 0.92 (d, 3H, J=6.5 Hz), 0.85 (d, 3H, J=6.5 Hz); MS (ESI+) m/z 251 (M+H).

1. customA 100-mL single-neck round-bottomed flask equipped with a magnetic stirrer
2. concentrationAfter this time, the reaction mixture was concentrated under reduced pressure
3. customthe resulting residue was partitioned between 10% aqueous potassium carbonate (100 mL) and methylene chloride (75 mL)
4. customThe layers were separated
5. extractionthe aqueous phase was extracted with methylene chloride (2×75 mL)
6. dry with materialThe combined organic extracts were dried over sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure