Chlorotrifluoroethylene → 7-Fluoro-1,2,3,4-tetrahydronaphthalen-1-one

HRID 1591446Notes

Reaction equation

HRID 1591446 reaction equation
[C:1]([F:6])(F)=[C:2](Cl)F.N1C=CC=CC=1.F.NC1C=[C:23]2[C:18]([CH2:19][CH2:20][CH2:21][C:22]2=[O:25])=[CH:17][CH:16]=1.N([O-])=O.[Na+]>N1C=CC=CC=1>[F:6][C:1]1[CH:2]=[C:23]2[C:18]([CH2:19][CH2:20][CH2:21][C:22]2=[O:25])=[CH:17][CH:16]=1

Participants

6

Reactant 4

HCID 6594ChlorotrifluoroethyleneHCID 64774Pyridine, hydrofluoride (1:1)2×HCID 3271777-Amino-1,2,3,4-tetrahydronaphthalen-1-oneHCID 23668193Sodium Nitrite

Product 1

HCID 103747647-Fluoro-1,2,3,4-tetrahydronaphthalen-1-oneYield 56%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Conditions

Temperature
90 °C

Procedure

In a specially designed Kel-F reactor (cylindrical shape 1.25"od×3"h equipped with a screw cap and N2 inlet-outlet) was placed hydrogen fluoride-pyridine 6:4 solution (10 mL, prepared by diluting commercially available hydrogen fluoride-pyridine 7:3 solution with dry pyridine). 7-amino-tetralone (644 mg, 4.0 mmol), (Example 35, Step A) was added under N2 and the solution was cooled to 0°. Sodium nitrite (304 mg, 4.4 mol, 1.1 eq) was added in portions and the mixture was stirred for 30 minutes. The mixture was then heated at 90° C. for 1 hour with stirring. The reaction mixture was quenched with approx. 60 mL of ice/water and the solid that separated extracted with methylene chloride (3×30 mL). The combined extracts were washed with water and brine, dried over magnesium sulfate, filtered and evaporated to dryness under vacuum at room temperature. Purification by flash chromatography on silica, eluting with ethyl acetate/hexane (5:95), afforded pure 7-fluoro- 1-tetralone (367 mg, 2.2 mmol, 56%). 1H NMR (300 MHz, CDCl3): 2.13 (m,2H), 2.65 (t,7 Hz,2H), 2.94 (t,7 Hz,2H), 7.1-7.3 (m,2H), 7.69 (dd;2,8 Hz;1H). EI-MS: calculated for C10H9FO 164; found 164 (M+,71%).

Workup

  1. custom×3"h equipped with a screw
  2. customcap
  3. customN2 inlet-outlet) was placed
  4. temperaturethe solution was cooled to 0°
  5. stirringwith stirring
  6. customThe reaction mixture was quenched with approx. 60 mL of ice/water
  7. customthe solid that separated
  8. extractionextracted with methylene chloride (3×30 mL)
  9. washThe combined extracts were washed with water and brine
  10. dry with materialdried over magnesium sulfate
  11. filtrationfiltered
  12. customevaporated to dryness under vacuum at room temperature
  13. customPurification by flash chromatography on silica
  14. washeluting with ethyl acetate/hexane (5:95)

Sources & evidence

ORD record
ord-b8cb1334541d49b7a7d35e6c70aad869
Source dataset
uspto-grants-1993_04
Patent number
US05206235

Reaction notes

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