2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → ethyl 5-bromo-8-carbamoyl-9H-carbazole-2-carboxylate

HRID 661894Notes

Reaction equation

HRID 661894 reaction equation
[Br:1][C:2]1[CH:14]=[CH:13][C:12]([C:15](=[O:17])[NH2:16])=[C:11]2[C:3]=1[C:4]1[CH2:5][CH2:6][CH:7]([C:18]([O:20][CH2:21][CH3:22])=[O:19])[CH2:8][C:9]=1[NH:10]2.ClC1C(=O)C(C#N)=C(C#N)C(=O)C=1Cl>C1(C)C=CC=CC=1>[Br:1][C:2]1[CH:14]=[CH:13][C:12]([C:15](=[O:17])[NH2:16])=[C:11]2[C:3]=1[C:4]1[CH:5]=[CH:6][C:7]([C:18]([O:20][CH2:21][CH3:22])=[O:19])=[CH:8][C:9]=1[NH:10]2

Participants

4

Reactant 2

HCID 67752,3-Dichloro-5,6-dicyano-1,4-benzoquinoneHCID 59375013ethyl 5-bromo-8-carbamoyl-2,3,4,9-tetrahydro-1H-carbazole-2-carboxylate2×

Product 1

HCID 59375100ethyl 5-bromo-8-carbamoyl-9H-carbazole-2-carboxylateYield 83.4%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A stirred suspension of ethyl 5-bromo-8-carbamoyl-2,3,4,9-tetrahydro-1H-carbazole-2-carboxylate (Intermediate 47-1, 9.31 g, 25.5 mmol) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (12.73 g, 56.1 mmol) in toluene (127 mL) was heated at reflux for 3 h. The mixture was cooled to rt and the precipitate was collected by filtration, washed with toluene and water, and air dried. The solid was suspended in methanol and the precipitate was collected by filtration, washed with methanol and air dried to provide ethyl 5-bromo-8-carbamoyl-9H-carbazole-2-carboxylate (7.68 g). The filtrate was concentrated and the residue was suspended in methanol. The precipitate was collected by filtration, washed with methanol and air dried to provide additional product (0.60 g) for a total of 8.28 g (90%). 1H NMR (400 MHz, DMSO-d6) δ 12.03 (s, 1H) 8.69 (d, J=8.57 Hz, 1H) 8.51 (d, J=1.10 Hz, 1H) 8.26 (br. s., 1H) 7.93 (d, J=8.13 Hz, 1H) 7.87 (dd, J=8.57, 1.54 Hz, 1H) 7.63 (br. s., 1H) 7.50 (d, J=8.13 Hz, 1H) 4.37 (q, J=7.03 Hz, 2H) 1.37 (t, J=7.14 Hz, 3H). Mass spectrum m/z 361, 363 (M+H)+.

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 3 h
  3. filtrationthe precipitate was collected by filtration
  4. washwashed with toluene and water, and air
  5. customdried
  6. filtrationthe precipitate was collected by filtration
  7. washwashed with methanol and air
  8. customdried

Sources & evidence

ORD record
ord-b4d73e44d1c04b28ae337231712ffaa4
Source dataset
uspto-grants-2011_12
Patent number
US08084620B2

Reaction notes

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