4-Sulfophthalic acid → 3-Hydroxybenzoic Acid

HRID 223424

Reaktionsgleichung

Reaktionsgleichung von HRID 223424
[Na].S([C:6]1[CH:14]=[CH:13][CH:12]=[C:8]([C:9]([OH:11])=[O:10])[C:7]=1C(O)=O)(O)(=O)=O.S(C1C=C(C(O)=O)C(=CC=1)C(O)=O)(O)(=O)=[O:19].[OH-].[Na+]>[Ni]>[OH:19][C:6]1[CH:7]=[C:8]([CH:12]=[CH:13][CH:14]=1)[C:9]([OH:11])=[O:10]

Komponenten

6

Edukt 4

HCID 69624-Sulfophthalic acidHCID 14798Sodium HydroxideHCID 1059701,2-Benzenedicarboxylic acid, 3-sulfo-HCID 5360545Sodium

Produkt 1

HCID 74203-Hydroxybenzoic AcidAusbeute 97 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 935NickelKatalysator

Reaktionsbedingungen

Temperatur
80 °C

Versuchsvorschrift

403.9 g (91.4%), corresponding to 369 g (100%), (1.5 mols), of the dry monosodium salt of a mixture of 3-sulphophthalic acid and 4-sulphophthalic acid are added to 960 g of 50% strength sodium hydroxide solution (12 mols of NaOH), which have been initially introduced into a nickel autoclave with a capacity of 1.3 l. The autoclave is closed and kept at a temperature of 260° C. for a period of 10 hours, during which time a maximum pressure of 28 bars is set up. After the reaction has ended, the contents of the autoclave are allowed to cool, the suspension is removed and the reactor is rinsed with about 1000 ml of water. The suspension is warmed to 80° C. and introduced carefully, in the course of 1 hour, into a mixture of 1500 ml of crude concentrated hydrochloric acid and 300 g of ice, whilst stirring vigorously. Vigorous evolution of gas due to the carbon dioxide and sulphur dioxide liberated is observed. After all of the mixture has run in, residues of sulphur dioxide are driven off by warming for two hours at 90° C., and the mixture is then cooled slowly to room temperature. The crystal slurry which is filtered off is dried in a vacuum drying cabinet at 90° C. and 20 mm Hg and gives a yield of 201 g (97% of theory) of 3-hydroxybenzoic acid with a purity of 99.9%. The water content is 0.01% and the sodium chloride content is 0.1%. No other impurities are detectable.

Aufarbeitung

  1. customThe autoclave is closed
  2. temperatureto cool
  3. customthe suspension is removed
  4. washthe reactor is rinsed with about 1000 ml of water
  5. additionintroduced carefully, in the course of 1 hour, into a mixture of 1500 ml of crude concentrated hydrochloric acid and 300 g of ice
  6. temperatureby warming for two hours at 90° C.
  7. temperaturethe mixture is then cooled slowly to room temperature
  8. filtrationThe crystal slurry which is filtered off
  9. customis dried in a vacuum
  10. customdrying cabinet at 90° C.

Quellen und Nachweise

ORD-Eintrag
ord-bc920fcacb5d4688b5729b35d19fa942
Quelldatensatz
uspto-grants-1982_10
Patentnummer
US04354038

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