反应详情

A mixture of 36.8 g (130 mmol) of 2-carbomethoxy-N,N-diacetyl-3,4-dimethoxyaniline and 500 mL of 2N NaOH was prepared and heated to reflux to obtain a clear brown solution. After refluxing for 5 hours, the reaction mixture was treated with Darco and filtered through a Hyflo bed to give a clear yellow solution. Glacial acetic acid (65 mL) was added and the reaction mixture was extracted with 2×500 mL of methylene chloride. Drying over sodium sulfate and rotary evaporation gave 19.5 g (76%) of crude white product. Recrystallization from ethyl acetate-hexane gave 15.4 g (60%) of the product as a white crystalline solid, mp 92.5°-95.0° C. NMR (CDCl3) δ 3.78 (s, 3H, OCH3), 4.02 (s, 3H, OCH3), 6.45 (d, 1H, J=10 Hz, ArH), 7.00 (d, 1H, J=10 Hz, ArH), 7.60 (br s, 3 H, CO2H and NH2).

1. customwas prepared
2. temperatureheated
3. temperatureto reflux
4. customto obtain a clear brown solution
5. temperatureAfter refluxing for 5 hours
6. filtrationfiltered through a Hyflo bed
7. customto give a clear yellow solution
8. extractionthe reaction mixture was extracted with 2×500 mL of methylene chloride
9. dry with materialDrying over sodium sulfate and rotary evaporation
10. customgave 19.5 g (76%) of crude white product
11. customRecrystallization from ethyl acetate-hexane