Hydrochloric Acid → 5-(propan-2-yl)-1H-indole-2,3-dione

HRID 1081265Notes

Reaction equation

HRID 1081265 reaction equation
[CH3:1][CH:2]([C:4]1[CH:10]=[CH:9][C:7]([NH2:8])=[CH:6][CH:5]=1)[CH3:3].Cl.Cl.N[OH:14].O.O.O.O.O.O.O.O.O.O.S([O-])([O-])(=O)=O.[Na+].[Na+].Cl[C:33](Cl)(Cl)[CH:34]([OH:36])O>O.C(O)C>[CH3:1][CH:2]([C:4]1[CH:5]=[C:6]2[C:7](=[CH:9][CH:10]=1)[NH:8][C:33](=[O:14])[C:34]2=[O:36])[CH3:3]

Participants

8

Reactant 5

HCID 313Hydrochloric AcidHCID 2707Chloral HydrateHCID 74644-IsopropylanilineHCID 62649Sodium sulfate decahydrateHCID 443297Hydroxyamine hydrochloride

Product 1

HCID 5898025-(propan-2-yl)-1H-indole-2,3-dione

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent4×

Conditions

Temperature
80 °C

Procedure

4-(1-Methylethyl)-aniline (6.75 g) was dissolved in water (30 ml) containing concentrated hydrochloric acid (4.4 ml). Hydroxylamine hydrochloride (16.9 g) in water (48 ml) and sodium sulphate decahydrate (100 g) in water (120 ml) were added, followed by chloral hydrate (16.5 g) in ethanol (180 ml). The reaction mixture was heated under reflux for 3 hours, then poured into water. The solid isonitroso-acetanilide intermediate was collected by filtration, washed and dried. This material was cooled in an ice-salt bath and concentrated sulphuric acid (48 ml) was added dropwise with stirring. After addition was complete the mixture was warmed to 80° C. for 20 minutes and then poured onto crushed ice. The resulting red solid was collected by filtration, washed, dried and then recrystallised from toluene-light petroleum to give the title compound, m.p. 127°-129° C.

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureunder reflux for 3 hours
  3. filtrationThe solid isonitroso-acetanilide intermediate was collected by filtration
  4. washwashed
  5. customdried
  6. temperatureThis material was cooled in an ice-salt bath
  7. additionconcentrated sulphuric acid (48 ml) was added dropwise
  8. additionAfter addition
  9. additionpoured
  10. customonto crushed ice
  11. filtrationThe resulting red solid was collected by filtration
  12. washwashed
  13. customdried
  14. customrecrystallised from toluene-light petroleum

Sources & evidence

ORD record
ord-6fbb5b4d21a2410f94baa38992075c21
Source dataset
uspto-grants-1996_12
Patent number
US05585378

Reaction notes

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