Tetrabutylammonium Fluoride → 2-(1-Methylethyl)-5-nitro-1H-indole

HRID 1964321Notes

Reaction equation

HRID 1964321 reaction equation
C([NH:6][C:7]1[CH:12]=[CH:11][C:10]([N+:13]([O-:15])=[O:14])=[CH:9][C:8]=1[C:16]#[C:17][C:18]([CH3:24])(C)[C:19](OC)=O)(=O)CCC.CCCC[N+](CCCC)(CCCC)CCCC.[F-]>CN(C=O)C>[CH:18]([C:17]1[NH:6][C:7]2[C:8]([CH:16]=1)=[CH:9][C:10]([N+:13]([O-:15])=[O:14])=[CH:11][CH:12]=2)([CH3:24])[CH3:19]

Participants

4

Reactant 2

HCID 2724141Tetrabutylammonium FluorideHCID 59129384HCID 59129384, compound

Product 1

HCID 107268712-(1-Methylethyl)-5-nitro-1H-indoleYield 33%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
70 °C

Procedure

A mixture of methyl 4-(2-butyramido-5-nitrophenyl)-2,2-dimethylbut-3-ynoate (0.50 g, 1.5 mmol) and TBAF (790 mg, 3.0 mmol) in DMF (20 mL) was heated at 70° C. for 24 h. The reaction mixture was cooled to room temperature and poured into ice water. The mixture was extracted with ether (30 mL×3). The combined organic layers were dried over anhydrous Na2SO4 and evaporated under reduced pressure to give a residue, which was purified by column chromatography on silica gel (petroleum ether/ethyl acetate=20/1) to give 2-isopropyl-5-nitro-1H-indole (100 mg, 33%). 1H NMR (400 MHz, CDCl3) δ 8.68 (s, 1 H), 8.25 (br s, 1 H), 8.21 (dd, J=2.4, 10.0 Hz, 1 H), 7.32 (d, J=8.8 Hz, 1 H), 6.41 (s, 1 H), 3.07-3.14 (m, 1 H), 1.39 (d, J =6.8 Hz, 6 H).

Workup

  1. temperatureThe reaction mixture was cooled to room temperature
  2. extractionThe mixture was extracted with ether (30 mL×3)
  3. dry with materialThe combined organic layers were dried over anhydrous Na2SO4
  4. customevaporated under reduced pressure
  5. customto give a residue, which
  6. customwas purified by column chromatography on silica gel (petroleum ether/ethyl acetate=20/1)

Sources & evidence

ORD record
ord-88fa421325ba46c9a2413e0faa077d26
Source dataset
uspto-grants-2013_04
Patent number
US08415387B2

Reaction notes

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