Hydrazine → Pyridine, 2,3,5-trichloro-

Temperature

92 °C

A mixture was prepared containing 50.3 grams (0.2 mole) of pentachloropyridine, 20 grams (0.24 mole) of sodium bicarbonate and 6.9 grams (0.205 mole) of 95 percent hydrazine in 215 milliliters of propylene glycol methyl ether. The mixture was heated at 92° C., with stirring, for 1.5 hours. The mixture was cooled to 30° C. and 50 milliliters of propylene glycol methyl ether was added. To this mixture was added 350 milliliters of a 10 percent sodium hypochlorite solution, over a 20 minute period while the temperature of the solution was maintained at 45°-50° C. At the completion of the reaction, the solution was diluted with 100 milliliters of water and extracted with hexane. The hexane extract was washed with water and the hexane evaporated off. The oily product which remained was dissolved in 250 milliliters of propylene glycol methyl ether and 20 grams of sodium bicarbonate and 6.9 grams of 95 percent hydrazine were added thereto. The mixture was heated at 92° C. for 1.5 hours and 1.0 gram of 95 percent hydrazine was added. Heating was continued for 3 additional hours and the reaction mixture was cooled to 45° C. To this mixture was added 450 milliliters of a 10 percent sodium hypochlorite solution over a 20 minute period while maintaining the reaction temperature at 45°-50° C. The reaction mixture was extracted with hexane and the hexane extract was washed with water and the hexane was removed by evaporation. The crude 2,3,5-trichloropyridine product was obtained in a yield of 30.5 grams and found to be 94.6 percent pure.

1. customA mixture was prepared
2. temperatureThe mixture was cooled to 30° C.
3. temperatureover a 20 minute period while the temperature of the solution was maintained at 45°-50° C
4. customAt the completion of the reaction
5. extractionextracted with hexane
6. extractionThe hexane extract
7. washwas washed with water
8. customthe hexane evaporated off
9. dissolutionThe oily product which remained was dissolved in 250 milliliters of propylene glycol methyl ether
10. addition20 grams of sodium bicarbonate and 6.9 grams of 95 percent hydrazine were added
11. temperatureThe mixture was heated at 92° C. for 1.5 hours
12. addition1.0 gram of 95 percent hydrazine was added
13. temperatureHeating
14. temperaturethe reaction mixture was cooled to 45° C
15. additionTo this mixture was added 450 milliliters of a 10 percent sodium hypochlorite solution over a 20 minute period
16. temperaturewhile maintaining the reaction temperature at 45°-50° C
17. extractionThe reaction mixture was extracted with hexane
18. extractionthe hexane extract
19. washwas washed with water
20. customthe hexane was removed by evaporation

ORD record

ord-41016dc2adfb4f9cae9031dbc2bf5e31

Source dataset

uspto-grants-1978_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04127575