Phenylhydrazine → ethyl 2,3,4,9-tetrahydro-1h-carbazole-3-carboxylate

HRID 1417467Notes

Reaction equation

HRID 1417467 reaction equation
[C:1]1([NH:7]N)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.O=[C:10]1[CH2:15][CH2:14][CH:13]([C:16]([O:18][CH2:19][CH3:20])=[O:17])[CH2:12][CH2:11]1>C(O)(=O)C>[CH2:15]1[C:10]2[NH:7][C:1]3[C:2](=[CH:3][CH:4]=[CH:5][CH:6]=3)[C:11]=2[CH2:12][CH:13]([C:16]([O:18][CH2:19][CH3:20])=[O:17])[CH2:14]1

Participants

4

Reactant 2

HCID 7516PhenylhydrazineHCID 317638Ethyl 4-oxocyclohexanecarboxylate

Product 1

HCID 282360ethyl 2,3,4,9-tetrahydro-1h-carbazole-3-carboxylateYield 93.8%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

A solution of 1.08 g of phenylhydrazine and 1.84 g of ethyl 4-oxocyclohexanecarboxylate in 25 ml of acetic acid was refluxed for 30 minutes and then poured into ice water. The aqueous layer was extracted with ethyl acetate. The organic extract was washed thoroughly with a saturated aqueous solution of sodium hydrogencarbonate, dried over anhydrous magnesium sulfate, and concentrated by evaporation under reduced pressure. The resulting residue was subjected to column chromatography using 50 g of silica gel with a 4:1 v/v mixture of hexane and ethyl acetate as the eluent and then recrystallized from ethyl acetate and hexane, to yield 2.28 g of the title compound, melting at 95°-96° C.

Workup

  1. extractionThe aqueous layer was extracted with ethyl acetate
  2. extractionThe organic extract
  3. washwas washed thoroughly with a saturated aqueous solution of sodium hydrogencarbonate
  4. dry with materialdried over anhydrous magnesium sulfate
  5. concentrationconcentrated by evaporation under reduced pressure
  6. additionwith a 4:1 v/v mixture of hexane and ethyl acetate as the eluent
  7. customrecrystallized from ethyl acetate and hexane

Sources & evidence

ORD record
ord-258238ed4aa54987977f24d550082bc1
Source dataset
uspto-grants-1999_03
Patent number
US05877199

Reaction notes

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