反应详情

Crude methyl 3-formyl-4-(methyloxy)benzoate from the previous step was dissolved in 40 mL of dioxane with stirring. Sulfamic acid (5.87 g, 60.5 mmol) in 20 mL of H2O was added to the stirring solution. Sodium chlorite (1.68 g, 80% by weight, 18.6 mmol) in 20 mL of H2O was added dropwise via addition funnel. The reaction was stirred for 40 min and poured into EtOAc and H2O. The layers were separated, and the organic layer was washed with brine. The combined aqueous layers were extracted with EtOAc, and the combined organic layers were dried over MgSO4, filtered, and concentrated in vacuo. The solid was transferred to an Erlenmeyer flask with the aid of 30-40 mL of DCM. Approximately 50 mL of hexanes was added. Air was blown over the solution to allow most of the DCM to evaporate. Diethyl ether was added (20-30 mL), and the suspension was filtered. The solid was washed with hexanes, collected, and dried to afford 1.96 g (82% over 2 steps) of the desired compound. 1H NMR (400 MHz, DMSO-d6): δ 12.92 (br s, 1H), 8.22 (d, J=2.2 Hz, 1H), 8.07 (dd, J=8.8, 2.2 Hz, 1H), 7.24 (d, J=8.8 Hz, 1H), 3.88 (s, 3H), 3.82 (s, 3H).

1. stirringThe reaction was stirred for 40 min
2. customThe layers were separated
3. washthe organic layer was washed with brine
4. extractionThe combined aqueous layers were extracted with EtOAc
5. dry with materialthe combined organic layers were dried over MgSO4
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. additionApproximately 50 mL of hexanes was added
9. customto evaporate
10. additionDiethyl ether was added (20-30 mL)
11. filtrationthe suspension was filtered
12. washThe solid was washed with hexanes
13. customcollected
14. customdried