2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → 1,2,3,6-Tetrahydro-1,3-dioxo-4-phenylpyrrolo[3,4-c]carbazole

HRID 1165797

Reaction equation

HRID 1165797 reaction equation
[O:1]=[C:2]1[CH:17]2[CH:5]([CH:6]([C:18]3[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=3)[CH2:7][C:8]3[NH:9][C:10]4[CH:11]=[CH:12][CH:13]=[CH:14][C:15]=4[C:16]=32)[C:4](=[O:24])[NH:3]1.C(C1C(=O)C(Cl)=C(Cl)C(=O)C=1C#N)#N.CC(C)=O.C(OC(C)C)(C)C>C1(C)C=CC=CC=1>[O:1]=[C:2]1[C:17]2[C:16]3[C:15]4[CH:14]=[CH:13][CH:12]=[CH:11][C:10]=4[NH:9][C:8]=3[CH:7]=[C:6]([C:18]3[CH:19]=[CH:20][CH:21]=[CH:22][CH:23]=3)[C:5]=2[C:4](=[O:24])[NH:3]1

Participants

5

Reactant 3

HCID 67752,3-Dichloro-5,6-dicyano-1,4-benzoquinoneHCID 198609951,2,3,3a,4,5,6,10c-Octahydro-1,3-dioxo-4-phenylpyrrolo[3,4-c]carbazoleHCID 22221350Acetone diisopropyl ether

Product 1

HCID 146772861,2,3,6-Tetrahydro-1,3-dioxo-4-phenylpyrrolo[3,4-c]carbazole

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

1.2 g (3.8 mmole) 1,2,3,3a,4,5,6,10c-octahydro-1,3-dioxo-4-phenylpyrrolo[3,4-c]carbazole and 2.2 g (9.7 mmole) DDQ are heated under reflux for 20 hours in 30 ml toluene. The solvent is distilled off in a vacuum and the residue chromatographed on silica gel with toluene/ethyl acetate 3:1. The fraction with the Rf of 0.3 is isolated, stirred up with acetone/diisopropyl ether, and the crystals formed are filtered off. One obtains 1,2,3,6-tetrahydro-1,3-dioxo-4-phenyl-pyrrolo[3,4-c]carbazole in the form of yellow crystals of the mp 262°-263° C.

Workup

  1. distillationThe solvent is distilled off in a vacuum
  2. customthe residue chromatographed on silica gel with toluene/ethyl acetate 3:1
  3. customThe fraction with the Rf of 0.3 is isolated
  4. customthe crystals formed
  5. filtrationare filtered off

Sources & evidence

ORD record
ord-b7ab31f1740948d19c3791905d1ce535
Source dataset
uspto-grants-1990_03
Patent number
US04912107

Linked notes

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