Carbazole → 1,6-Dihydrocyclopenta[c]carbazol-3(2H)-one

HRID 1615014Notes

Reaction equation

HRID 1615014 reaction equation
[N+:1]([C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=1[C:10]1[CH:18]=[CH:17][CH:16]=[C:15]2[C:11]=1[CH2:12][CH2:13][C:14]2=[O:19])([O-])=O.P(OCC)(OCC)OCC.C1C2NC3C(=CC=CC=3)C=2C=CC=1>CCOCC>[CH2:12]1[C:11]2[C:10]3[C:5]4[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=4[NH:1][C:18]=3[CH:17]=[CH:16][C:15]=2[C:14](=[O:19])[CH2:13]1

Participants

5

Reactant 3

HCID 6854CarbazoleHCID 31215Triethyl phosphiteHCID 585449044-(2-Nitrophenyl)indan-1-one

Product 1

HCID 585448961,6-Dihydrocyclopenta[c]carbazol-3(2H)-oneYield 61.8%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Conditions

Temperature
90 °C

Procedure

Compound 45 (5.0 g) was divided into five portions (1.0 g each). P(OEt)3 (per 7 mL) was added to each portion. The resulting product was subjected to argon blow in a flask, heated to 90° C., kept at this temperature for 3 days, then cooled. The carbazole precipitate was diluted with ether. The precipitate was filtered and washed with ether. If the initial biphenyl was present in the filtrate (TLC monitoring, eluent: hexane-ethyl acetate, 1:1), this filtrate was evaporated, then P(OEt)3 was added (1 mL to each flask), and subjected to cyclization for 1 day. The procedure was repeated until the precipitation ceased and TLC showed the absence of the initial biphenyl. Carbazol 46 (2.7 g) was obtained.

Workup

  1. customThe resulting product was subjected to argon blow in a flask
  2. temperaturecooled
  3. filtrationThe precipitate was filtered
  4. washwashed with ether
  5. customthis filtrate was evaporated
  6. additionP(OEt)3 was added (1 mL to each flask)
  7. waitsubjected to cyclization for 1 day
  8. customThe procedure was repeated until the precipitation

Sources & evidence

ORD record
ord-4229050550824619a455fa06ac061a61
Source dataset
uspto-grants-2014_07
Patent number
US08765738B2

Reaction notes

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