反应详情

A suspension of 34.2 g. of 2,6-dimethoxy-4-(methoxy-carbonyl)-carbanilic acid benzyl ester and 5.8 g. of sodium hydride (50% dispersion in oil) in 300 ml. of absolute dimethylformamide was stirred at room temperature for 4 hours. The resulting solution was treated with 17 g. of methyl iodide with stirring and ice-cooling. After stirring at room temperature for 1 hour, the dimethylformamide was removed under vacuum at 60° C. Then, 1 liter of water was added to the residue and the emulsion was extracted with two 2 liter portions of ethyl acetate. The organic phases were washed with two 1 liter portions of water, dried over magnesium sulfate and evaporated under vacuum. After recrystallization of the residue from alcohol, there was obtained 2,6-dimethoxy-4-(methoxy-carbonyl)-N-methyl-carbanilic acid benzyl ester having a melting point of 130°-131° C.

1. additionA suspension of 34.2 g
2. additionThe resulting solution was treated with 17 g
3. temperatureice-cooling
4. customthe dimethylformamide was removed under vacuum at 60° C
5. additionThen, 1 liter of water was added to the residue
6. extractionthe emulsion was extracted with two 2 liter portions of ethyl acetate
7. washThe organic phases were washed with two 1 liter portions of water
8. dry with materialdried over magnesium sulfate
9. customevaporated under vacuum
10. customAfter recrystallization of the residue from alcohol