Sodium hydride → 5-{3-[2-(Ethoxycarbonyl)-1-trifluoromethyl-vinyl]ureido}-6-fluoro-3-(2-propynyl)-2-benzothiazolinone

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Reaction Steps

A solution of 18.51 g of ethyl 3-amino-4,4,4-trifluorocrotonate in 50 ml of dimethylformamide is added dropwise while stirring at 0° C. during 30 minutes to 4.41 g of a 55% sodium hydride dispersion in 100 ml of dimethylformamide and the mixture is stirred at room temperature for 2 hours. The reaction mixture is then cooled to -55° C. and treated during 3 minutes while stirring with a solution of 25.10 g of 6-fluoro-5-isocyanato-3-(2-propynyl)-2-benzothiazolinone in 200 ml of dimethylformamide/toluene (1:1). In so doing, the temperature of the reaction mixture rises to -15° C. and the mixture is subsequently stirred at room temperature for one hour. The thus-formed intermediate 5-{3-[2-(ethoxycarbonyl)-1-trifluoromethyl-vinyl]ureido}-6-fluoro-3-(2-propynyl)-2-benzothiazolinone is not isolated.

Provenance & Evidence