Bromide ion → 6,6′-Diiodo[1,1′-biphenyl]-3,3′-diol

HRID 619768Notes

Reaction equation

HRID 619768 reaction equation
[I:1][C:2]1[CH:7]=[CH:6][C:5]([O:8]C)=[CH:4][C:3]=1[C:10]1[CH:15]=[C:14]([O:16]C)[CH:13]=[CH:12][C:11]=1[I:18].[Br-].Br.B(Br)(Br)Br>ClCCl>[I:1][C:2]1[CH:7]=[CH:6][C:5]([OH:8])=[CH:4][C:3]=1[C:10]1[CH:15]=[C:14]([OH:16])[CH:13]=[CH:12][C:11]=1[I:18]

Participants

6

Reactant 4

HCID 259Bromide ionHCID 260Hydrogen BromideHCID 25134Boron tribromideHCID 10895916HCID 10895916, compound

Product 1

HCID 226253006,6′-Diiodo[1,1′-biphenyl]-3,3′-diol

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

The second 2,2'-dihalo-5,5'-dimethoxybiphenyl, and preferably 2,2'-diiodo-5,5'-dimethoxybiphenyl, is then demethylated under temperatures of about -78° C. to about -20° C., and preferably from about -78° C. to about -50° C., and ambient pressure, with a bromide-containing compound such as hydrogen bromide, boron tribromide, or mixtures thereof in a chlorinated solvent such as a chlorohydrocarbon including but not limited to dichloromethane to yield 2,2'-dihalo-5,5'-dihydroxybiphenyl, and preferably 2,2'-diiodo-5,5'-dihydroxybiphenyl. Boron tribromide is the preferred reactant. The concentration of the bromide-containing compound in the chlorinated solvent may range from 0.05M to about 1M, and preferably from about 0.1M to about 0.5M. The period of the demethylation reaction may depend upon the chemical structure, but will generally be from about 5 minutes to about 2 hours, and preferably from about 15 minutes to about 1 hour. The molar ratio of 2,2'-diiodo-5,5'dimethoxybiphenyl to the bromide-containing compound is about 1:3 to 1:10, and preferably about 1:2.5 to 1:5.

Workup

  1. customis then demethylated under temperatures of about -78° C. to about -20° C.

Sources & evidence

ORD record
ord-887ccedd0e0e4bbf848460a242c8abf5
Source dataset
uspto-grants-1999_09
Patent number
US05959157

Reaction notes

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