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

HRID 839420Notes

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

110 parts of monomethyl maleate are added with stirring to 800 parts of water containing 152 parts of p-hydrazinobenzene sulphonate and 88 parts of sodium carbonate. The mixture is warmed until all reactants are in solution and the pH is adjusted by addition of sodium carbonate to 7.0. The resulting solution is heated at 100° C for 9 hours during which period the pH is adjusted to 7.0 after 6 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 filtered off and dried between 50°-100° C. The actual weight yield is 266 parts of strength 77% (determined by N.M.R.) which represents a yield of 85% theory.

Workup

temperatureThe mixture is warmed until all reactants
temperatureOn completion of heating

Sources & evidence

ORD record: ord-046cfddd66d842988d0e86b3e26fec6f
Source dataset: uspto-grants-1978_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04095024

Reaction notes

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