Ammonium Hydroxide → 1,2-Difluoronaphthalene

HRID 2182108Notes

Reaction equation

HRID 2182108 reaction equation
[F:1][C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[C:5](F)=[C:4](F)[C:3]=1[F:14].FC1(F)C2C(=CC=CC=2)C=CC1(F)F.[NH4+].[OH-]>C1COCC1.[Zn]>[F:1][C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[CH:5]=[CH:4][C:3]=1[F:14]

Participants

6

Reactant 3

HCID 14923Ammonium HydroxideHCID 120705341,1,2,2-Tetrafluoro-1,2-dihydronaphthaleneHCID 123439521,2,3,4-Tetrafluoronaphthalene

Product 1

HCID 111374671,2-DifluoronaphthaleneYield 95%

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 8028TetrahydrofuranSolvent

Procedure

A solution of the tetrafluoro naphthalene, 1,1,2,2-tetrafluoro-1,2-dihydronaphthalene (5.25 g , 25.66 mmol) in THF (15 ml) was treated with 30% aqueous NH4OH (30 ml) and zinc (8.45 g, 130 mmol) (powder) and stirred under N2 for 4 hours at RT. The reaction was monitored by GC/MS for disappearance of the starting material and found to be complete. The solution was filtered, extracted with hexane (30 ml), and filtered through a short silica column (20 g). The hexane solution was evaporated in vacuo to afford an oil. This crystallized on cooling to room temperature to afford 3.99 g (95% yield) of product. MS: m/e 164 (M+).

Workup

  1. filtrationThe solution was filtered
  2. extractionextracted with hexane (30 ml)
  3. filtrationfiltered through a short silica column (20 g)
  4. customThe hexane solution was evaporated in vacuo
  5. customto afford an oil
  6. customThis crystallized
  7. temperatureon cooling to room temperature

Sources & evidence

ORD record
ord-c53e1639735d4ffa95c75ab0ec5f7439
Source dataset
uspto-grants-2005_05
Patent number
US06894200B2

Reaction notes

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