4-Chloro-2-fluoro-5-methoxyaniline → 4-Chloro-2-fluoro-5-methoxyphenylhydrazine

Temperature

0 °C

A stirred solution of 48.0 g (0.27 mole) of 4-chloro-2-fluoro-5-methoxyaniline in 500 mL of concentrated hydrochloric acid was cooled to -5° C. and 23.5 g (0.34 mole) of sodium nitrite in 100 mL of water was added dropwise. After complete addition, the reaction mixture was stirred at 0° C. for one hour. A second solution of 154.0 g (0.68 mole) of stannous chloride in 225 mL of concentrated hydrochloric acid was cooled to 0° C., and the cold diazonium solution prepared above was added to it slowly. After complete addition, the reaction mixture was allowed to warm to ambient temperature. The reaction mixture was filtered to collect a solid. This solid was dissolved in an aqueous 50% sodium hydroxide solution, and the solution extracted with toluene. The toluene extract was dried with magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure to yield 22.4 g of 4-chloro-2-fluoro-5-methoxyphenylhydrazine as a solid.

1. additionAfter complete addition
2. additionabove was added to it slowly
3. additionAfter complete addition
4. temperatureto warm to ambient temperature
5. filtrationThe reaction mixture was filtered
6. customto collect a solid
7. dissolutionThis solid was dissolved in an aqueous 50% sodium hydroxide solution
8. extractionthe solution extracted with toluene
9. extractionThe toluene extract
10. dry with materialwas dried with magnesium sulfate
11. filtrationfiltered
12. concentrationThe filtrate was concentrated under reduced pressure

ORD record

ord-6511e6987a1c4ee1873ed713aca873ec

Source dataset

uspto-grants-1987_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04705557