Process for the preparation of 4-hydroxybiphenyl
AssigneeBayer Aktiengesellschaft
InventorsHorst Behre, Helmut Fiege, Gunter Rauchschwalbe
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Abstract
4-Hydroxybiphenyl is obtained in non-thixotropic form if a reaction mixture which is obtained by alkaline hydrolysis of biphenyl-4-sulfonic acid and contains 4-hydroxybiphenyl is heated at elevated pressure at above 115.degree. C. and at a pH from 0 to below 6.5.
Claims11
A process for the preparation of 4-hydroxybiphenyl in the form of a non-thixotropic moist product with a water content of 10 to 20% by weight from biphenyl-4-sulfonic acid by alkaline hydrolysis with alkali metal hydroxide, which comprises heating the hydrolysis mixture, after dilution with water and neutralization with a mineral acid, at a temperature above 115.degree. C. to 170.degree. C. and at a pH of 0 to below 6.5.
Dependencies are inferred from the claim text.