Phenylhydrazine → Sodium 2-phenylhydrazonobenzenesulfonate

HRID 1534776Notes

Reaction equation

HRID 1534776 reaction equation
[C:1]1([NH:7][NH2:8])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.C([C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][C:12]=1[S:17]([O-:20])(=[O:19])=[O:18])=O.[Na+:21]>CO>[C:1]1([NH:7][N:8]=[C:13]2[CH:14]=[CH:15][CH:16]=[CH:11][CH:12]2[S:17]([O-:20])(=[O:19])=[O:18])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[Na+:21]

Participants

4

Reactant 2

HCID 7516PhenylhydrazineHCID 3794540Sodium o-formylbenzenesulfonate

Product 1

HCID 86745497Sodium 2-phenylhydrazonobenzenesulfonateYield 89.6%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent2×

Procedure

104 g of phenylhydrazine was dissolved in 800 ml of methanol, and a solution obtained by dissolving 56 g of sodium o-formylbenzenesulfonate in 200 ml of methanol was dropwise added thereto at room temperature. The resulting mixture was heated for 2 hours under reflux with stirring. After cooling, the crystal formed was separated by filtration and then washed with methanol to obtain 69 g of sodium 2-phenylhydrazonobenzenesulfonate (Intermediate A). 50 g of Intermediate A thus obtained was dissolved in 250 ml of water and then hydrogenated in an autoclave by adding palladium-carbon catalyst thereto. After the catalyst was removed by filtration, 250 ml of isopropanol was added to the hydrogenated product whereupon a colorless product precipitated out. This product was separated out by filtration and washed with isopropanol and then dried to obtain 43 g of sodium 2-phenylhydrazinobenzenesulfonate (Intermediate B). Next, 40 g of Intermediate B, 19 g of diethyl malonate, 25 g of sodium methylate (28% methanol solution) and 100 ml of n-butanol were blended and heated for 10 hours under reflux. N-butanol was concentrated and 200 ml of water was added to the residue. Next, the aqueous layer was made acidic with concentrated hydrochloric acid, whereby a crystal precipitated out. This was separated out by filtration and washed with a small amount of methanol to give 39 g of Intermediate C (1-phenyl-2-(2-sulfobenzyl)- 3,5-pyrazolidinedione sodium salt).

Workup

  1. customa solution obtained
  2. additionwas dropwise added
  3. customat room temperature
  4. temperatureThe resulting mixture was heated for 2 hours
  5. temperatureunder reflux
  6. temperatureAfter cooling
  7. customthe crystal formed
  8. customwas separated by filtration
  9. washwashed with methanol

Sources & evidence

ORD record
ord-88b9c266155a42399b9aaf7b5669dfaa
Source dataset
uspto-grants-1992_02
Patent number
US05091295

Reaction notes

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