Ethyl 3-oxocyclohexanecarboxylate → 6-bromo-2-(ethoxycarbonyl)-2,3,4,9-tetrahydro-1H-carbazole-8-carboxylic acid

HRID 2410666Notes

Reaction equation

HRID 2410666 reaction equation
Cl.Cl.[Br:3][C:4]1[CH:5]=[CH:6][C:7]([NH:13]N)=[C:8]([CH:12]=1)[C:9]([OH:11])=[O:10].O=[C:16]1[CH2:21][CH2:20][CH2:19][CH:18]([C:22]([O:24][CH2:25][CH3:26])=[O:23])[CH2:17]1>C(O)(=O)C.C(OCC)(=O)C>[Br:3][C:4]1[CH:5]=[C:6]2[C:7](=[C:8]([C:9]([OH:11])=[O:10])[CH:12]=1)[NH:13][C:16]1[CH2:17][CH:18]([C:22]([O:24][CH2:25][CH3:26])=[O:23])[CH2:19][CH2:20][C:21]2=1

Participants

5

Reactant 2

HCID 118096Ethyl 3-oxocyclohexanecarboxylateHCID 666052955-Bromo-2-hydrazinylbenzoic acid dihydrochloride

Product 1

HCID 666048536-bromo-2-(ethoxycarbonyl)-2,3,4,9-tetrahydro-1H-carbazole-8-carboxylic acidYield 57.3%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 8857Ethyl AcetateSolvent

Procedure

A cream colored suspension of 5-bromo-2-hydrazinylbenzoic acid dihydrochloride (6 g, 19.74 mmol) and ethyl 3-oxocyclohexanecarboxylate (3.70 g, 21.71 mmol) in glacial acetic acid, (˜0.4M) (45 mL) was heated at reflux for 4h. The reaction mixture turned in to dark yellow suspension. The reaction mixture was cooled to room temperature and it was concentrated to afford a dark yellow solid. The solid was then suspended in ethyl acetate (˜50 ml) and the solid was filtered, washed with water and ethyl acetate to give 4.14 g of 6-bromo-2-(ethoxycarbonyl)-2,3,4,9-tetrahydro-1H-carbazole-8-carboxylic acid. MS (ESI) m/z 366.3 (M+H). 1H NMR (DMSO-d6) δ ppm 13.4-12.3 (b, 1H), 10.99 (s, 1H), 7.79 (d, 1H, J=1.9 Hz) 7.69 (d, 1H, J=1.8 Hz), 4.08-4.17 (m, 2H), 3.05 (dd, 1H, J=16.5, 5.0), 2.97-2.84 (m, 2H), 2.76-2.69 (m, 1H), 2.67-2.59 (m, 1H), 2.19-2.12 (m, 1H), 1.88-1.78 (m, 1H), 1.21 (t, 3H, J=7.2).

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 4h
  3. concentrationit was concentrated
  4. customto afford a dark yellow solid
  5. filtrationthe solid was filtered
  6. washwashed with water and ethyl acetate

Sources & evidence

ORD record
ord-5dc1790e7f144a079f7cff411bcb057f
Source dataset
uspto-grants-2014_08
Patent number
US08815840B2

Reaction notes

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