Sodium hydride → Isopropyl 2-chloro-4-fluoro-5-{3-[2-(ethoxycarbonyl)-2-fluoro-1-fluoromethyl-vinyl]ureido}-benzoate

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Reaction Steps

A solution of 1.80 g of ethyl 3-amino-2,4-difluorocrotonate in 20 ml of absolute dimethylformamide is added dropwise with stirring during 10 minutes to 0.48 g of a 55% sodium hydride dispersion in 25 ml of dimethylformamide at room temperature, and the mixture is stirred for a further 15 minutes. Thereafter 2.81 g of isopropyl 2-chloro-4-fluoro-5-isocyanatobenzoate are added, with the result that the temperature of the reaction mixture rises to 35° C. Then the mixture is stirred for a further two hours at room temperature. The isopropyl 2-chloro-4-fluoro-5-{3-[2-(ethoxycarbonyl)-2-fluoro-1-fluoromethyl-vinyl]ureido}-benzoate formed as an intermediate is not isolated.

Provenance & Evidence