Water → 3-methyl-2,3,4,9-tetrahydro-1H-carbazole-8-carboxylic acid

HRID 617807

Reaktionsgleichung

Reaktionsgleichung von HRID 617807
Cl.[NH:2]([C:4]1[CH:12]=[CH:11][CH:10]=[CH:9][C:5]=1[C:6]([OH:8])=[O:7])N.[CH3:13][CH:14]1[CH2:19][CH2:18][C:17](=O)[CH2:16][CH2:15]1.O>C(O)(=O)C>[CH3:13][CH:14]1[CH2:19][CH2:18][C:17]2[NH:2][C:4]3[C:5]([C:6]([OH:8])=[O:7])=[CH:9][CH:10]=[CH:11][C:12]=3[C:16]=2[CH2:15]1

Komponenten

5

Edukt 3

HCID 962WaterHCID 115254-MethylcyclohexanoneHCID 104169Benzoic acid, 2-hydrazinyl-, hydrochloride (1:1)

Produkt 1

HCID 212396693-methyl-2,3,4,9-tetrahydro-1H-carbazole-8-carboxylic acidAusbeute 87,2 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 176Acetic AcidLösungsmittel

Versuchsvorschrift

A suspension of 2.0 g (10.6 mmol) of 2-hydrazinobenzoic acid hydrochloride in acetic acid (20 ml) was slowly boiled under stirring and 1.2 ml (9.8 mmol) of 4-methylcyclohexanone was dropped thereinto. The obtained mixture was heated under reflux for 8 hours and then allowed to cool. After adding water, the precipitate thus formed was recovered by filtration, washed with water and dried to thereby give 1.96 g of 6-methyl-5,6,7,8-tetrahydro-9H-carbazole-1-carboxylic acid. This product was dissolved in acetone (50 ml) and 2.1 ml (34 mmol) of methyl iodide and 2.35 g (17 mmol) of anhydrous potassium carbonate were added thereto. The reaction mixture was heated under reflux under stirring for 2 hours, then allowed to cool and extracted with water and ethyl acetate. The organic layer was taken up, washed with water, dried over magnesium sulfate and concentrated to dryness. Thus 1.49 g of methyl 6-methyl-5,6,7,8-tetrahydro-9H-carbazole-1-carboxylate was obtained. This product was suspended in diphenyl ether (10 ml) and 890 mg of 10% palladium-carbon was added thereto. The obtained mixture was heated under reflux under stirring in a nitrogen atmosphere for 1 hour. After allowing to cool, It was dissolved by adding tetrahydrofuran. Then the catalyst was filtered off and the filtrate was concentrated. After adding n-hexane, the crystals thus formed were recovered by filtration to thereby give 1.26 g of the title compound.

Aufarbeitung

  1. temperatureThe obtained mixture was heated
  2. temperatureunder reflux for 8 hours
  3. temperatureto cool
  4. customthe precipitate thus formed
  5. filtrationwas recovered by filtration
  6. washwashed with water
  7. customdried

Quellen und Nachweise

ORD-Eintrag
ord-4735c306df9f463aa3b211f084addeb6
Quelldatensatz
uspto-grants-1999_09
Patentnummer
US05952335

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