Hydrochloric Acid → Methyl 2-(2,4-difluorophenylamino)-5-fluoro-6-phenylthionicotinate

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Reaction Steps

In 39 ml of N,N-dimethylformamide was dissolved 3.89 g of methyl 2-(2,4-difluorophenylamino)-5-fluoro-6-(mesitylenesulfonyloxy)nicotinate, and to the resulting solution were added 1.34 g of thiophenol and 1.23 g of triethylamine, after which the resulting mixture was subjected to reaction at room temperature for 5 hours. Subsequently, 120 ml of ethyl acetate and 120 ml of water were added to the reaction mixture, and the pH of the mixture was adjusted to 2.0 with 2N hydrochloric acid. The organic layer was separated, washed successively with 80 ml of water and 80 ml of saturated aqueous sodium chloride solution, and then dried over anhydrous magnesium sulfate. The solvent was removed by distillation under reduced pressure, and to the crystalline material thus obtained was added 20 ml of n-hexane, after which the crystals thus deposited were collected by filtration to obtain 2.85 g (yield 90.2%) of methyl 2-(2,4-difluorophenylamino)-5-fluoro-6-phenylthionicotinate having a melting point of 126°-128° C. The physical properties of this compound were identical with those of the compound obtained in Example 7.

Provenance & Evidence