Trichloroisocyanuric Acid → 3-Chloro-5-(trifluoromethyl)-2-pyridinamine

Participants

Reaction Steps

Into the same 300 ml four-necked flask as used in Example 1, 16.2 g (0.1 mol) of 2-amino-5-trifluoromethylpyridine prepared in the same manner as in step (1) of Example 1, 10.1 g (0.043 mol) of trichloroisocyanuric acid and 150 g of toluene were added, and the reaction was conducted at 110° C. for 3 hours under heating with stirring. During the reaction, formation of 2-chloroamino-5-trifluoromethylpyridine was confirmed. After completion of the reaction, the reaction mixture was cooled to room temperature, and 100 g of a 25% sodium hydroxide aqueous solution was added thereto and stirred. An aqueous layer and an oil layer were separated. A 20% hydrochloric acid aqueous solution was added to the oil layer, and the mixture was stirred. An aqueous layer and an oil layer were further separated. The aqueous layer was neutralized with a 25% sodium hydroxide aqueous solution. Precipitated slightly yellow crystals were collected by filtration and dried to obtain 17.6 g 2-amino-3-chloro- 5-trifluoromethylpyridine (purity as measured by liquid chromatography: 95%, yield: 85%).

Provenance & Evidence