Ammonium Hydroxide → 1,2-Difluoronaphthalene

HRID 2182109Notes

Reaction equation

HRID 2182109 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].BrC1C=C2C(=CC=1)C(F)(F)C(F)(F)C=C2.[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 123439521,2,3,4-TetrafluoronaphthaleneHCID 224834376-Bromo-1,1,2,2-tetrafluoro-1,2-dihydronaphthalene

Product 1

HCID 111374671,2-DifluoronaphthaleneYield 95%

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 8028TetrahydrofuranSolvent

Procedure

A solution of the tetrafluoro naphthalene, 6-bromo-1,1,2,2-tetrafluoro-1,2-dihydronaphthalene (4.74 g, 16.80 mmol) in THF (15 ml) was treated with 30% aqueous NH4OH (30 ml) and zinc (8.45 g, 130 mmol) and stirred under N2 for 24 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 2.62 g (95% yield) of product.

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-3b03b91615c44d2cb19f899240417f06
Source dataset
uspto-grants-2005_05
Patent number
US06894200B2

Reaction notes

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