Methyl iodide → 2,6-dimethoxy-4-(methoxy-carbonyl)-N-methyl-carbanilic acid benzyl ester

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Reaction Steps

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.

Provenance & Evidence