Sodium 2-phenylhydrazonobenzenesulfonate → Sodium 2-phenylhydrazinobenzenesulfonate

HRID 1534777Notes

Reaction equation

HRID 1534777 reaction equation
[C:1]1([NH:7][N:8]=[C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]2[S:15]([O-:18])(=[O:17])=[O:16])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[Na+:19]>O.[C].[Pd]>[C:1]1([NH:7][NH:8][C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][C:10]=2[S:15]([O-:18])(=[O:17])=[O:16])[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1.[Na+:19]

Participants

4

Reactant 1

HCID 86745497Sodium 2-phenylhydrazonobenzenesulfonate

Product 1

HCID 88358900Sodium 2-phenylhydrazinobenzenesulfonateYield 86%

Reagents, catalysts & solvents 2

HCID 178418390HCID 178418390, compoundCatalystHCID 962WaterSolvent

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. customAfter the catalyst was removed by filtration, 250 ml of isopropanol
  2. additionwas added to the hydrogenated product whereupon a colorless product
  3. customprecipitated out
  4. customThis product was separated out by filtration
  5. washwashed with isopropanol
  6. customdried

Sources & evidence

ORD record
ord-ed3da4c3f17a441f9fd7310c7654c891
Source dataset
uspto-grants-1992_02
Patent number
US05091295

Reaction notes

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