Phenol → 4-Phenoxy-4'-phenylethynylbenzophenone

HRID 1757682Notes

Reaction equation

F[C:2]1[CH:23]=[CH:22][C:5]([C:6]([C:8]2[CH:13]=[CH:12][C:11]([C:14]#[C:15][C:16]3[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=3)=[CH:10][CH:9]=2)=[O:7])=[CH:4][CH:3]=1.[C:24]1([OH:30])[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1.C(=O)([O-])[O-].[K+].[K+]>>[O:30]([C:2]1[CH:23]=[CH:22][C:5]([C:6]([C:8]2[CH:13]=[CH:12][C:11]([C:14]#[C:15][C:16]3[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=3)=[CH:10][CH:9]=2)=[O:7])=[CH:4][CH:3]=1)[C:24]1[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1

Participants

Reactant 3

HCID 996Phenol

HCID 11430Potassium Carbonate

HCID 40956574-Fluoro-4'-(phenylethynyl)benzophenone

Product 1

HCID 193892734-Phenoxy-4'-phenylethynylbenzophenoneYield 60%

Procedure

The phenylethynyl group has several unexpected advantages over the ethynyl based analog. See the Hergenrother and Delfort references supra. When 4-fluoro-4'-phenylethynylbenzophenone was treated with phenol in the presence of an alkali metal base such as potassium carbonate in a polar aprotic solvent at 160° C., the expected 4-phenoxy-4'-phenylethynylbenzophenone was afforded in nearly quantitativeyield. However, when 4-ethynyl-4'-fluorobenzophenone was used in the same procedure, the result was a mixture of products with a total yield of 60%.Several variations in the procedure were tried, but the resulting product was not exclusively tile expected ethynyl arylene-ether. This indicates that when the phenylethynyl endcapping compound is used to terminate nucleophilic reagents, the reaction proceeds qualitatively to afford the phenylethynyl terminated reactive oligomers exclusively. If the ethynyl adduct is used, a variety of products results.

Sources & evidence

ORD record: ord-221168d75b374422988418d9a8186818
Source dataset: uspto-grants-1995_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05446204

Reaction notes

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