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

Temperature

20 °C

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%).

1. additionwere added
2. additionAfter the dropwise addition
3. temperaturethe reaction mixture was heated to 80° C.
4. waitthe reaction was conducted for 10 hours
5. stirringwith stirring
6. customAfter completion of the reaction
7. temperaturethe reaction mixture was cooled to room temperature
8. customan aqueous layer and an oil layer were separated
9. additionA 20% hydrochloric acid aqueous solution was added to the oil layer
10. stirringthe mixture was stirred
11. customPrecipitated slightly yellow crystals
12. filtrationwere collected by filtration
13. customdried

ORD record

ord-633061011f6b4e67ace8302c8f157342

Source dataset

uspto-grants-1996_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05491239