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

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%).

1. additionwere added
2. temperatureunder heating
3. customAfter completion of the reaction
4. stirringstirred
5. customAn aqueous layer and an oil layer were separated
6. additionA 20% hydrochloric acid aqueous solution was added to the oil layer
7. stirringthe mixture was stirred
8. customPrecipitated slightly yellow crystals
9. filtrationwere collected by filtration
10. customdried

ORD record

ord-b4610ef4dd914cb3b0fcc62bd9ea040e

Source dataset

uspto-grants-1996_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05491239