Oblon, Spivak, McClelland, Maier & Neustadt
Preparation of 4,4'-dihydroxybiphenyl
 4,4'-dihydroxybiphenyl is prepared by treating biphenyl-4,4'-disulfonic acid or one of its alkali metal salts in an alkali metal hydroxide melt by a process in which the treatment is carried out in a melt which contains from 7 to 14 moles of potassium hydroxide and from 0 to 8 moles of sodium hydroxide, based in each case on 1 mole of biphenyl-4,4'-disulfonic acid, in the presence of an alkali metal carbonate at from 280.degree. to 360.degree. C. 
BASF Aktiengesellschaft
C
C07C
inventional
Ulrich Peter
Eichenauer Neumann