Benzenamine hydrochloride (1:1) → 3-Chloro-4-fluorophenylhydrazine

HRID 2198587Notes

Reaction equation

HRID 2198587 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]([CH:6]=[CH:7][C:8]=1[F:9])[NH2:5].Cl.[NH2:11]C1C=CC=CC=1.N([O-])=O.[Na+].[OH-].[Na+]>O.Cl>[Cl:1][C:2]1[CH:3]=[C:4]([NH:5][NH2:11])[CH:6]=[CH:7][C:8]=1[F:9]

Participants

7

Reactant 4

HCID 8870Benzenamine hydrochloride (1:1)HCID 97083-Chloro-4-fluoroanilineHCID 14798Sodium HydroxideHCID 23668193Sodium Nitrite

Product 1

HCID 27365753-Chloro-4-fluorophenylhydrazineYield 67%

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidSolvent2×HCID 962WaterSolvent

Conditions

Temperature
80 °C

Procedure

A mixture of 144.9 g of 3-chloro-4-fluoroaniline and 705 ml of concentrated hydrochloric acid was stirred and heated to 80° C. The mixture containing the aniline hydrochloride was allowed to cool to ambient temperature. After 24 hours, the mixture was stirred and cooled to 5°-10° C. while a solution of 69.5 g of sodium nitrite in 350 ml of water was added dropwise within 1/2 hour. After an additional 1/2 hour, the solution containing the diazonium salt was gradually added with stirring to a solution of 427 g of stannous chloride (2H2O) in 700 ml of hydrochloric acid. After 45 minutes at ambient temperature, the reaction mixture was made alkaline by the addition of 3000 ml of 50% sodium hydroxide and extracted with ether. The combined ether extracts were dried (MgSO4), filtered and concentrated to give 214.1 g (67%) of 3-chloro-4-fluorophenylhydrazine as a tan solid; melting point 75°-77° C.

Workup

  1. temperatureto cool to ambient temperature
  2. stirringthe mixture was stirred
  3. additionwas added dropwise within 1/2 hour
  4. waitAfter an additional 1/2 hour
  5. additionwas gradually added
  6. waitAfter 45 minutes at ambient temperature
  7. extractionextracted with ether
  8. dry with materialThe combined ether extracts were dried (MgSO4)
  9. filtrationfiltered
  10. concentrationconcentrated

Sources & evidence

ORD record
ord-80cf05555f20487d86df47439c769e0c
Source dataset
uspto-grants-1982_11
Patent number
US04358611

Reaction notes

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