N-isopropyl-6-nitro-1,2,3,4-tetrahydrocarbazole → N-isopropyl-6-amino-1,2,3,4-tetrahydrocarbazole

HRID 50606Notes

Reaction equation

HRID 50606 reaction equation
[CH:1]([N:4]1[C:16]2[CH2:15][CH2:14][CH2:13][CH2:12][C:11]=2[C:10]2[C:5]1=[CH:6][CH:7]=[C:8]([N+:17]([O-])=O)[CH:9]=2)([CH3:3])[CH3:2]>C(O)(=O)C.[Fe]>[CH:1]([N:4]1[C:16]2[CH2:15][CH2:14][CH2:13][CH2:12][C:11]=2[C:10]2[C:5]1=[CH:6][CH:7]=[C:8]([NH2:17])[CH:9]=2)([CH3:3])[CH3:2]

Participants

4

Reactant 1

HCID 22736139N-isopropyl-6-nitro-1,2,3,4-tetrahydrocarbazole

Product 1

HCID 12992579N-isopropyl-6-amino-1,2,3,4-tetrahydrocarbazoleYield 58.7%

Reagents, catalysts & solvents 2

HCID 23925IronCatalystHCID 176Acetic AcidSolvent

Conditions

Temperature
50 °C

Procedure

6-Nitro-1,2,3,4-tetrahydrocarbazole (5.04 g) prepared by the method described in Journal of Chemical Society, p.833 (1924) was dissolved in 50 mL of acetone, and the solution was added with 2.25 g of potassium hydroxide and 8.45 g of isopropyl iodide, warmed to 50° C. and stirred for 3 hours. The reaction mixture was added with water and the deposited precipitates were collected to obtain 2.60 g of N-isopropyl-6-nitro-1,2,3,4-tetrahydrocarbazole. The resulting N-isopropyl-6-nitro-1,2,3,4-tetrahydrocarbazole (2.60 g) was dissolved in 100 mL of acetic acid, and the solution was added with 2.75 g of iron powder, warmed to 50° C., and stirred for 3 hours. The reaction mixture was filtered and the filtrate was diluted by adding water. The reaction mixture was made basic with 1 N sodium hydroxide and extracted with dichloromethane. The organic layer was dried over anhydrous sodium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel chromatography (eluent: dichloromethane/ethyl acetate=7/3) to obtain 1.35 g of N-isopropyl-6-amino-1,2,3,4-tetrahydrocarbazole.

Workup

  1. filtrationThe reaction mixture was filtered
  2. additionthe filtrate was diluted
  3. additionby adding water
  4. extractionextracted with dichloromethane
  5. dry with materialThe organic layer was dried over anhydrous sodium sulfate
  6. customthe solvent was evaporated under reduced pressure
  7. customThe residue was purified by silica gel chromatography (eluent: dichloromethane/ethyl acetate=7/3)

Sources & evidence

ORD record
ord-0717e3e0760745c688dc67d21d4e0e69
Source dataset
uspto-grants-2004_03
Patent number
US06713473B1

Reaction notes

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