Sulfuric Acid → HCID 19738388, compound

HRID 2082549Notes

Reaction equation

HRID 2082549 reaction equation
[CH2:1]([C:3]1[CH:9]=[CH:8][C:6]([NH2:7])=[CH:5][CH:4]=1)[CH3:2].[S:10](=[O:14])(=[O:13])([OH:12])O.[OH:15][S:16](O)(=[O:18])=[O:17].O=S(=O)=O>>[CH2:1]([C:3]1[CH:4]=[C:5]([S:16]([OH:18])(=[O:17])=[O:15])[C:6](=[CH:8][C:9]=1[S:10]([OH:12])(=[O:14])=[O:13])[NH2:7])[CH3:2]

Participants

4

Reactant 3

HCID 1118Sulfuric Acid2×HCID 115044-Ethylaniline2×HCID 24681Fuming sulfuric acid

Product 1

HCID 19738388HCID 19738388, compoundYield 53%

Conditions

Temperature
80 °C

Procedure

121 parts of 4-ethylaniline are added dropwise at 75°-83° C. to 183 parts of 100% sulfuric acid. The mixture is stirred for 15 minutes at 80° C., whereupon a clear solution forms. This sulfuric acid solution is added dropwise over 40 minutes to 320 parts of 66% oleum, while keeping the temperature at 60°-65° C. by cooling with an ice bath. After stirring for 15 minutes at 65° C., no more 4-ethylaniline can be detected. Stirring is continued for 4 hours at 150° C., then the sulfonation mixture is cooled to 80° C. and poured into 900 parts of ice/water. The monopotassium salt of 4-ethylaniline-2,5-disulfonic acid is precipitated by the dropwise addition of 370 parts of a 50% solution of potassium hydroxide and isolated by filtration, affording 350 parts of moist 53.0% 4-ethylaniline-2,5-disulfonic acid, corresponding to a yield of 66%, based on 4-ethylaniline. The purity is >99% (analysis by HPLC).

Workup

  1. customat 60°-65° C.
  2. temperatureby cooling with an ice bath
  3. stirringAfter stirring for 15 minutes at 65° C.
  4. stirringStirring
  5. waitis continued for 4 hours at 150° C.
  6. temperaturethe sulfonation mixture is cooled to 80° C.
  7. customThe monopotassium salt of 4-ethylaniline-2,5-disulfonic acid is precipitated by the dropwise addition of 370 parts of a 50% solution of potassium hydroxide
  8. customisolated by filtration

Sources & evidence

ORD record
ord-bb38e21818774e9ea671a50e9d41ea73
Source dataset
uspto-grants-1993_02
Patent number
US05189206

Reaction notes

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