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 50 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. Upon complete addition, the reaction mixture was stirred at 0° C. for one hour. A 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 solution prepared above was slowly added to it. Upon complete addition, the reaction mixture was allowed to warm to ambient temperature, then was filtered to collect a solid. The solid was made basic and extracted with toluene. The toluene layer was separated and dried over magnesium sulfate, then filtered. The filtrate was concentrated under reduced pressure to give 22.4 g of 4-chloro-2-fluoro-5-methoxyphenylhdrazine as a solid.

1. additionUpon complete addition
2. customthe cold solution prepared above
3. additionwas slowly added to it
4. additionUpon complete addition
5. temperatureto warm to ambient temperature
6. filtrationwas filtered
7. customto collect a solid
8. extractionextracted with toluene
9. customThe toluene layer was separated
10. dry with materialdried over magnesium sulfate
11. filtrationfiltered
12. concentrationThe filtrate was concentrated under reduced pressure
13. customto give 22.4 g of 4-chloro-2-fluoro-5-methoxyphenylhdrazine as a solid

ORD record

ord-c8fed236597c48eb89649966643dec63

Source dataset

uspto-grants-1989_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04818276