HCID 519745, compound → HCID 20568685, compound

HRID 895037Notes

Reaction equation

HRID 895037 reaction equation
Br[C:2]1[C:7]([Br:8])=[C:6]([Cl:9])[C:5]([Br:10])=[C:4](Br)[C:3]=1[OH:12].[H][H]>[OH-].[K+].CO.[Ni]>[Br:8][C:7]1[CH:2]=[C:3]([OH:12])[CH:4]=[C:5]([Br:10])[C:6]=1[Cl:9]

Participants

6

Reactant 2

HCID 519745HCID 519745, compoundHCID 178418361HCID 178418361, compound2×

Product 1

HCID 20568685HCID 20568685, compoundYield 61%

Reagents, catalysts & solvents 3

HCID 935NickelCatalystHCID 887MethanolSolventHCID 14797Potassium HydroxideSolvent

Procedure

8.9 g of 2,3,5,6-tetrabromo-4-chlorophenol are dissolved in a mixture of 40 ml of 1 N methanolic KOH and 60 ml of methanol and then 4 g of Raney nickel are added to the solution. Hydrogenation is carried out with hydrogen in a shaking apparatus for 41/2 hours under normal pressure at 20° C. The uptake of hydrogen is 98% of theory. The catalyst is removed by filtration and the filtrate is concentrated. The residue is recrystallised twice from cyclohexane, affording 3.5 g of 3,5-dibromo-4-chlorophenol in the form of colourless crystals with a melting point of 121° C.

Workup

  1. custom2 hours
  2. customat 20° C
  3. customThe catalyst is removed by filtration
  4. concentrationthe filtrate is concentrated
  5. customThe residue is recrystallised twice from cyclohexane

Sources & evidence

ORD record
ord-c700916851094f12bdede7e2a84d8085
Source dataset
uspto-grants-1981_08
Patent number
US04285971

Reaction notes

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