Indole → Tetrahydrocyclopent(b)indole

HRID 2427254Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 2427254
O=[C:2]1[CH2:6][CH2:5][CH:4]([N:7]2[C:15](=O)[C:14]3[C:9](=[CH:10][CH:11]=[CH:12]C=3)C2=O)[CH2:3]1.C1(NN)C=CC=CC=1.N1C2C(=CC=CC=2)C=C1>>[CH2:2]1[C:3]2[CH:4]([N:7]=[C:15]3[C:14]=2[CH:9]=[CH:10][CH:11]=[CH:12]3)[CH2:5][CH2:6]1

Komponenten

4

Edukt 3

HCID 798IndoleHCID 7516PhenylhydrazineHCID 545940982-(3-Oxocyclopentyl)-1H-isoindole-1,3(2H)-dione

Produkt 1

HCID 66869719Tetrahydrocyclopent(b)indole

Versuchsvorschrift

In Scheme II, Step B, (±)-2-(3-oxo-cyclopentyl)-isoindole-1,3-dione (9) is reacted with a phenylhydrazine of formula (10) in a typical Fischer indole synthesis to give a tetrahydrocyclopenta[b]indole of formula (11). The skilled artisan will recognize that there are a variety of acidic conditions to effect a Fischer indole synthesis, including both proton and Lewis acids. The preferred conditions use a mixture of glacial acetic acid with 4N HCl in dioxane, at a temperature of 50° C. to the reflux temperature of the solvent, for about 4 to 24 hours. The product is isolated by addition of water followed by filtration of the resulting solid. The solid is sonicated in methanol to give material of sufficient purity. Alternatively, the reaction is effected using a Lewis acid, such as zinc chloride, in an amount of about 2 to 4 equivalents.

Quellen und Nachweise

ORD-Eintrag
ord-56a3b510010f453da3fc875567c5038f
Quelldatensatz
uspto-grants-2011_06
Patentnummer
US07968587B2

Notizen zur Reaktion

Wird geladen…