Sulfuric Acid → 2-Amino-4-chlorobenzene-1-sulfonic acid

HRID 2111957Notes

Reaction equation

HRID 2111957 reaction equation
[S:1](=[O:5])(=O)([OH:3])[OH:2].[Cl:6][C:7]1[CH:8]=[C:9]([CH:11]=[CH:12][CH:13]=1)[NH2:10]>O.[OH-].[Na+]>[NH2:10][C:9]1[CH:8]=[C:7]([Cl:6])[CH:13]=[CH:12][C:11]=1[S:1]([OH:3])(=[O:5])=[O:2]

Participants

5

Reactant 2

HCID 1118Sulfuric AcidHCID 79323-Chloroaniline

Product 1

HCID 2355042-Amino-4-chlorobenzene-1-sulfonic acidYield 48.2%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent3×HCID 14798Sodium HydroxideSolvent

Procedure

Concentrated sulphuric acid (specific gravity. 1.84) (13.9 ml, 250 mmol) was diluted with 100 ml of water. 3-Chloro-aniline (31.9 g, 250 mmol) was added over 30 minutes while temperature was kept at 85° C. During the addition some precipitation occurred. The suspension was allowed to cool to room temperature and heavy precipitation was formed. The solid is filtered with suction to yield white crystalline solid. The solid was heated slowly to 200° C. under vacuum (water pump) and fitted with a water trap. The solid was kept at 200° C. for 7 hours. Water was lost from the crystalline material. The solid was allowed to cool and then dissolved in dilute aqueous NaOH and precipitated with hydrochloric acid. Yielded 25 g (48%) of the title compound as a white crystalline solid (m.p. >250° C.).

Workup

  1. customwas kept at 85° C
  2. additionDuring the addition
  3. customsome precipitation
  4. customheavy precipitation
  5. customwas formed
  6. filtrationThe solid is filtered with suction
  7. customto yield white crystalline solid
  8. customfitted with a water trap
  9. temperatureto cool
  10. customprecipitated with hydrochloric acid

Sources & evidence

ORD record
ord-14a2fa2d1d4b4ac99dea57010adc63e1
Source dataset
uspto-grants-2009_04
Patent number
US07521480B2

Reaction notes

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