Hydrochloric Acid → 2-Amino-o-cresol

HRID 1459419Notes

Reaction equation

HRID 1459419 reaction equation
S(O)(=O)([C:3]1[CH:8]=[CH:7][C:6]([NH2:9])=[CH:5][CH:4]=1)=O.[C:12](=[O:15])([O-])[O-].[Na+].[Na+].N([O-])=O.[Na+].Cl.[OH-].[Na+].S(S([O-])=O)([O-])=O.[Na+].[Na+]>O.C([O-])(O)=O.[Na+]>[CH3:8][C:7]1[C:6]([NH2:9])=[CH:5][CH:4]=[CH:3][C:12]=1[OH:15]

Participants

9

Reactant 6

HCID 313Hydrochloric AcidHCID 8479Sulfanilic acidHCID 10340Sodium CarbonateHCID 14798Sodium HydroxideHCID 24489Sodium DithioniteHCID 23668193Sodium Nitrite

Product 1

HCID 1044482-Amino-o-cresol

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 516892Sodium BicarbonateSolvent

Conditions

Temperature
0 °C

Procedure

To a 500 mL erlenmeyer flask was added sulfanilic acid (14.38 g, 83 mmol), sodium carbonate (4.29 g, 40.5 mmol) and distilled H2O (83 mL), when all of the sulfanilic acid dissolved, the solution was cooled in an ice bath to 0° C. and a solution of sodium nitrite (6.16 g, 89.3 mmol) in H2O (15 mL) was added in one portion. The ice bath was allowed to warm to +15° C. and the mixture was stirred at this temperature 1 h. The reaction mixture was poured onto a mixture of ice (100 g) and 12N HCl (17.4 mL). The ice was allowed to melt and the solid diazonium salt was collected by suction filtration on a scintered glass frit. O-cresol (9.10 g, 84.1 mmol) was dissolved in a solution of NaOH (1.21 g, 30.25 mmol) in H2O (100 mL). This solution was cooled to 0° C. and the solid diazonium salt was added in one portion. This well stirred mixture was maintained at +15° C. for 4 h. The temperature of the mixture was raised to +60° C. and sodium dithionite (35 g, 1.03 mol) was added portionwise. The reaction was allowed to proceed at +60° C. for 15 min. The mixture was cooled to room temperature, diluted with saturated aqueous NaHCO3 and extracted with EtOAc. The EtOAc extract was dried (MgSO4), filtered, concentrated in vacuo and chromatographed on 100 g of silica gel using 1:3 EtOAc-hexane as eluant. There was obtained 2-methyl-3-amino-phenol as a tan solid.

Workup

  1. distillationdistilled H2O (83 mL), when all of the sulfanilic acid
  2. dissolutiondissolved
  3. temperatureto warm to +15° C.
  4. filtrationthe solid diazonium salt was collected by suction filtration on a scintered glass frit
  5. temperatureThis solution was cooled to 0° C.
  6. stirringThis well stirred mixture
  7. temperaturewas maintained at +15° C. for 4 h
  8. temperatureThe temperature of the mixture was raised to +60° C.
  9. waitto proceed at +60° C. for 15 min
  10. temperatureThe mixture was cooled to room temperature
  11. extractionextracted with EtOAc
  12. extractionThe EtOAc extract
  13. dry with materialwas dried (MgSO4)
  14. filtrationfiltered
  15. concentrationconcentrated in vacuo
  16. customchromatographed on 100 g of silica gel using 1:3 EtOAc-hexane as eluant

Sources & evidence

ORD record
ord-ef90058c4cbd40599460a2788b238910
Source dataset
uspto-grants-1998_12
Patent number
US05854245

Reaction notes

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