反应详情

To a solution of 3-amino-5-hydroxy-4-iodo-benzoic acid methyl ester (0.25 g, 0.85 mmol, 1.0 equiv) in DMF (3 mL) and ethyl iodide (0.10 mL, 0.146 g, 0.94 mmol, 1.1 equiv) at 0° C. was added sodium tert-butoxide (0.11 g, 0.94 mmol, 1.1 equiv) in small portions over a time period of 10 min. After stirring for 1 h, the cooling bath was removed and the the reaction mixture stirred at rt for an additional 18 h. The solution was concentrated by evaporation under reduced pressure and extracted with ethyl acetate (3×50 mL). The combined organic phases were dried over MgSO4, concentrated by evaporation under reduced pressure and the crude material purified with column chromatography on silica eluting with hexane/ethyl acetate (2:1) yielding 0.19 g (69%) of the title compound. 1H NMR (250 MHz, CDCl3): δ 1.49 (t, J=7.0 Hz, 3H), 3.89 (s, 3H), 4.11 (q, J=7.0 Hz, 2H), 4.33 (br s, 2H), 6.82 (d, J=2.7 Hz, 1H), 7.07 (d, J=2.7 Hz, 1H). MS (EI): 321.0 [M]+.

1. customthe cooling bath was removed
2. stirringthe the reaction mixture stirred at rt for an additional 18 h
3. concentrationThe solution was concentrated by evaporation under reduced pressure
4. extractionextracted with ethyl acetate (3×50 mL)
5. dry with materialThe combined organic phases were dried over MgSO4
6. concentrationconcentrated by evaporation under reduced pressure
7. customthe crude material purified with column chromatography on silica eluting with hexane/ethyl acetate (2:1)