Sodium Dithionite → 3-(5-(Trifluoromethyl)-1,2,4-oxadiazol-3-yl)aniline

HRID 1397299Notes

Reaction equation

HRID 1397299 reaction equation
S(S([O-])=O)([O-])=O.[Na+].[Na+].[N+:9]([C:12]1[CH:13]=[C:14]([C:18]2[N:22]=[C:21]([C:23]([F:26])([F:25])[F:24])[O:20][N:19]=2)[CH:15]=[CH:16][CH:17]=1)([O-])=O>[Br-].C([N+](CCCC)(CCCC)CCCC)CCC.C1COCC1.O>[F:25][C:23]([F:24])([F:26])[C:21]1[O:20][N:19]=[C:18]([C:14]2[CH:13]=[C:12]([CH:17]=[CH:16][CH:15]=2)[NH2:9])[N:22]=1

Participants

5

Reactant 2

HCID 24489Sodium DithioniteHCID 5505713-(3-Nitrophenyl)-5-(trifluoromethyl)-1,2,4-oxadiazole

Product 1

HCID 202975493-(5-(Trifluoromethyl)-1,2,4-oxadiazol-3-yl)anilineYield 57.2%

Reagents, catalysts & solvents 2

HCID 74236Tetrabutylammonium BromideCatalystHCID 21881883Oxolane--water (1/1)Solvent

Procedure

Sodium dithionite (1.61 g, 9.2 mmol) and a catalytic amount of tetra-n-butylammonium bromide (20 mg) were added to a solution of 3-(3-nitrophenyl)-5-(trifluoromethyl)-1,2,4-oxadiazole (1.6 g, 6.1 mmol) in THF—H2O (30 mL, 1:1 v/v), and the reaction mixture was stirred at room temperature for 2 h and monitored by TLC (petroleum ether/EtOAc 1:1). Solvent was removed under reduced pressure and the product was extracted with EtOAc. The organic layer was washed with brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The crude product was purified by column chromatography (silica gel 60-120 mesh, eluent 30-35% EtOAc in petroleum ether) to afford 3-(5-(trifluoromethyl)-1,2,4-oxadiazol-3-yl)aniline (0.8 g, yield 57%). 1H NMR (300 MHz, CDCl3) δ 7.52-7.49 (dt, J=7.7 Hz, 1.2 Hz, 1H), 7.42 (m, 1H), 7.30 (t, J=8.0 Hz, 1H), 6.89-6.86 (ddd, J=7.9 Hz, 2.4 Hz, 0.9 Hz, 1H), 3.87 (br s, 2H). MS (ESI) m/z: Calculated for C9H6F3N3O: 229.05. found: 230.0 (M+H)+.

Workup

  1. customSolvent was removed under reduced pressure
  2. extractionthe product was extracted with EtOAc
  3. washThe organic layer was washed with brine
  4. dry with materialdried over anhydrous sodium sulfate
  5. concentrationconcentrated under reduced pressure
  6. customThe crude product was purified by column chromatography (silica gel 60-120 mesh, eluent 30-35% EtOAc in petroleum ether)

Sources & evidence

ORD record
ord-d8d5fe73c02f4b54a502449235a1f286
Source dataset
uspto-grants-2014_12
Patent number
US08901156B2

Reaction notes

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