2-Amino-5-(trifluoromethyl)pyridine → 3-Chloro-5-(trifluoromethyl)-2-pyridinamine

Participants

Reaction Conditions

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 and 150 g of toluene were added, and 42.2 g of a 30% sodium dichloroisocyanurate aqueous solution (sodium dichloroisocyanurate: 0.0575 mol) was dropwise added thereto over a period of one hour while stirring at 20° C. After the dropwise addition, the reaction mixture was heated to 80° C., and the reaction was conducted for 10 hours 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 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 15.7 g 2-amino-3-chloro-5-trifluoromethylpyridine (purity as measured by liquid chromatography: 96%, yield: 77%).

Provenance & Evidence