Hydrochloric Acid → 5-Oxo-1-(4-sulfophenyl)pyrazolidine-3-carboxylic acid

HRID 839423Notes

Reaction equation

[C:1]([O:8]C)(=[O:7])/[CH:2]=[CH:3]\[C:4]([O-])=[O:5].[NH:10]([C:12]1[CH:17]=[CH:16][C:15]([S:18]([O-:21])(=[O:20])=[O:19])=[CH:14][CH:13]=1)[NH2:11].C(=O)([O-])[O-].[Na+].[Na+].Cl>O>[C:1]([CH:2]1[CH2:3][C:4](=[O:5])[N:10]([C:12]2[CH:17]=[CH:16][C:15]([S:18]([OH:21])(=[O:19])=[O:20])=[CH:14][CH:13]=2)[NH:11]1)([OH:8])=[O:7]

Participants

Conditions

Temperature: 100 °C

Procedure

50 parts of monomethyl maleate are added with stirring to 400 parts of water containing 70 parts of p-hydrazinobenzene sulphonate and 39 parts of sodium carbonate. The mixture is warmed until all reactants are in solution and the pH is adjusted by sodium carbonate to 9.2. The resulting solution is heated at 100° C for 9 hours. On completion of heating, the pH is adjusted to 3.8 by addition of hydrochloric acid and the 3-carboxy-1-(4'-sulphophenyl)-5-pyrazolidone thus formed is recovered and dried between 50°-100° C. The actual weight yield is 140 parts of strength 70% (determined by N.M.R.) which represents a yield of 89% of the theory.

Workup

temperatureThe mixture is warmed until all reactants
temperatureOn completion of heating

Sources & evidence

ORD record: ord-45b863d13b1a4adda52f0d8bce9265c1
Source dataset: uspto-grants-1978_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04095024

Reaction notes

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