Hydrochloric Acid → 7-Methylisatin

HRID 371321

Reaktionsgleichung

Reaktionsgleichung von HRID 371321
Cl[C:2](Cl)(Cl)[CH:3]([OH:5])O.[OH2:8].O.O.O.O.O.O.O.O.O.S([O-])([O-])(=O)=O.[Na+].[Na+].[CH3:25][C:26]1[CH:32]=[CH:31][CH:30]=[CH:29][C:27]=1[NH2:28].Cl.Cl.NO>O>[CH3:25][C:26]1[CH:32]=[CH:31][CH:30]=[C:29]2[C:27]=1[NH:28][C:2](=[O:8])[C:3]2=[O:5]

Komponenten

7

Edukt 5

HCID 313Hydrochloric AcidHCID 2707Chloral HydrateHCID 7242O-ToluidineHCID 62649Sodium sulfate decahydrateHCID 443297Hydroxyamine hydrochloride

Produkt 1

HCID 143137-Methylisatin

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 962WaterLösungsmittel3×

Reaktionsbedingungen

Temperatur
75 °C

Versuchsvorschrift

In a 5 l flask is placed chloral hydrate (90 g, 0.54 mole) and water (1200 ml). To this solution is added sodium sulfate decahydrate (1300 g, 10.9 mole) followed by a solution of o-methylaniline (54 g, 0.5 mole) in water (300 ml) containing concentrated hydrochloric acid (43 ml, 0.5 mole). Then a solution of hydroxylamine hydrochloride (110 g, 1.58 mole) in water (50 ml) is added. The reaction mixture is heated to reflux over a 90 minute period and refluxed 30 minutes. The reaction is cooled in ice and the resulting crystalline ortho-isonitrosoacetotoluidide is isolated by filtration and air dried. The orthoisonitrosoacetotoluidide is dissolved in portions in concentrated sulfuric acid (325 ml) that is preheated to 50° C. with vigorous stirring. The reaction temperature is maintained under 75° C. When the addition is complete, the mixture is heated at 80° C. for 30 minutes, cooled, and poured unto ice (3 kg). The 7-methylisatin is isolated by filtration. The 7-methylisatin is purified by dissolution in dilute sodium hydroxide. The basic solution is treated with 4N hydrochloric acid until a slight amount of precipitation is evident. The mixture is filtered and the filtrate is acidified. The pure 7-methylisatin is recovered by filtration and dried in vacuo at 80° C. and 0.1 mm pressure, mp 114°-145° C. (A. Wahl, et al., Ann. Chim. 5 314 (1926).

Aufarbeitung

  1. customIn a 5 l flask is placed
  2. temperatureThe reaction mixture is heated
  3. temperatureto reflux over a 90 minute period
  4. temperaturerefluxed 30 minutes
  5. temperatureThe reaction is cooled in ice
  6. customthe resulting crystalline ortho-isonitrosoacetotoluidide is isolated by filtration and air
  7. customdried
  8. dissolutionThe orthoisonitrosoacetotoluidide is dissolved in portions in concentrated sulfuric acid (325 ml) that
  9. customis preheated to 50° C. with vigorous stirring
  10. additionWhen the addition
  11. temperaturethe mixture is heated at 80° C. for 30 minutes
  12. temperaturecooled
  13. additionpoured unto ice (3 kg)

Quellen und Nachweise

ORD-Eintrag
ord-ed67c224f9204c95818dfe119248d86b
Quelldatensatz
uspto-grants-1985_07
Patentnummer
US04530929

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