Sulfuric Acid → 2-Tert-butyl-5-nitroaniline

HRID 2251845Notes

Reaction equation

HRID 2251845 reaction equation
OS(O)(=O)=O.[C:6]([C:10]1[CH:16]=[CH:15][CH:14]=[CH:13][C:11]=1[NH2:12])([CH3:9])([CH3:8])[CH3:7].[N+:17]([O-])([O-:19])=[O:18].[K+]>>[N+:17]([C:14]1[CH:15]=[CH:16][C:10]([C:6]([CH3:9])([CH3:7])[CH3:8])=[C:11]([CH:13]=1)[NH2:12])([O-:19])=[O:18]

Participants

4

Reactant 3

HCID 1118Sulfuric AcidHCID 24434Potassium Nitrate2×HCID 805742-tert-Butylaniline

Product 1

HCID 8261032-Tert-butyl-5-nitroaniline

Procedure

Concentrated H2SO4 (1 L) was cooled to −10° C. with a dry ice-iPrOH bath in a 2 L 3-neck round bottom flask fitted with a mechanical stirrer and temperature probe. 2-t-Butylaniline (109 g, 730 mmol) was added, giving a clumpy solid. Once the temperature of the mixture was stabilized at −10° C., KNO3 (101 g, 1001 mmol) was added portion wise, as the solid, over 4 h, maintaining the temperature between −20 and −5° C. Once all of the KNO3 was added, the reaction was stirred overnight with gradual warming to RT. The reaction was quenched by diluting with water then extracted with EtOAc (3×). The EtOAc extracts were washed multiple times with saturated NaHCO3(aq), until gas evolution ceased, then with brine. The EtOAc extracts were combined, dried over anhydrous Na2SO4, filtered and concentrated under reduced pressure giving a black oil. The oil was eluted through a 36×7 cm column of silica gel with a 5%; 10%; 15%; 25%; and 50% EtOAc:Hexanes step gradient (2 L each step) giving a red solid.

Workup

  1. customfitted with a mechanical stirrer
  2. customgiving a clumpy solid
  3. customwas stabilized at −10° C.
  4. temperaturemaintaining the temperature between −20 and −5° C
  5. customThe reaction was quenched
  6. additionby diluting with water
  7. extractionthen extracted with EtOAc (3×)
  8. washThe EtOAc extracts were washed multiple times with saturated NaHCO3(aq)
  9. dry with materialdried over anhydrous Na2SO4
  10. filtrationfiltered
  11. concentrationconcentrated under reduced pressure
  12. customgiving a black oil
  13. washThe oil was eluted through a 36×7 cm column of silica gel with a 5%
  14. customand 50% EtOAc:Hexanes step gradient (2 L each step) giving a red solid

Sources & evidence

ORD record
ord-a44c2053cb114b3f92ada0dc0e141828
Source dataset
uspto-grants-2008_01
Patent number
US07320992B2

Reaction notes

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