Acetic Anhydride → Acetic acid N'-(2,4-dichloro-phenyl)-hydrazide

HRID 1359515Notes

Reaction equation

HRID 1359515 reaction equation
Cl.[Cl:2][C:3]1[CH:8]=[C:7]([Cl:9])[CH:6]=[CH:5][C:4]=1[NH:10][NH2:11].[OH-].[Na+].[C:14](OC(=O)C)(=[O:16])[CH3:15]>O>[C:14]([NH:11][NH:10][C:4]1[CH:5]=[CH:6][C:7]([Cl:9])=[CH:8][C:3]=1[Cl:2])(=[O:16])[CH3:15]

Participants

5

Reactant 3

HCID 7918Acetic AnhydrideHCID 14798Sodium Hydroxide2×HCID 2723905(2,4-Dichlorophenyl)hydrazine monohydrochloride

Product 1

HCID 612615Acetic acid N'-(2,4-dichloro-phenyl)-hydrazideYield 98%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent4×

Conditions

Temperature
10 °C

Procedure

A slurry of 101.4 grams (0.4751 mole) of 2,4-dichlorophenylhydrazine hydrochloride in 600 mL of water was stirred, and a solution of 20.9 grams (0.5225 mole) of sodium hydroxide in 100 mL of water was slowly added. During the addition, the reaction mixture thickened. An additional 50 mL of water was added to aid fluidity. Upon completion of addition of the sodium hydroxide solution, an additional 70 mL of water was added. The reaction mixture was stirred for about 75 minutes, then it was extracted with three 300 mL portions of ethyl acetate. The extracts were combined and dried with magnesium sulfate. The mixture was filtered and the filtrate containing free 2,4-dichlorophenylhydrazine (1) was transferred to an appropriate reaction vessel. The stirred solution was cooled to about 10° C., and 58.2 grams (0.5701 mole) acetic anhydride was added dropwise. Upon completion of addition, gas chromatographic (GC) analysis of the reaction mixture indicated the reaction was about 99% complete. The cooling medium was removed, and a solution of 62.5 grams of potassium carbonate in 200 mL of water was added to the reaction mixture. The mixture was stirred for about five minutes and the organic layer was separated. The organic layer was concentrated under reduced pressure, yielding 102.0 grams (98% yield) of 1-acetyl-2-(2,4-dichlorophenyl)hydrazine (2).

Workup

  1. additionDuring the addition
  2. extractionit was extracted with three 300 mL portions of ethyl acetate
  3. dry with materialdried with magnesium sulfate
  4. filtrationThe mixture was filtered
  5. additionthe filtrate containing free 2,4-dichlorophenylhydrazine (1)
  6. customwas transferred to an appropriate reaction vessel
  7. additionUpon completion of addition, gas chromatographic (GC) analysis of the reaction mixture
  8. customThe cooling medium was removed
  9. additiona solution of 62.5 grams of potassium carbonate in 200 mL of water was added to the reaction mixture
  10. stirringThe mixture was stirred for about five minutes
  11. customthe organic layer was separated
  12. concentrationThe organic layer was concentrated under reduced pressure

Sources & evidence

ORD record
ord-19b9c56a3143476f873d768256ff9e1b
Source dataset
uspto-grants-2003_07
Patent number
US06600049B2

Reaction notes

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