Patent ID: 6191316
Filing Date: 2001-02-20
Classification: C07C,Y02P

Abstract:
In the working up the mother liquor obtained in the process for producing a dihydroxydiarylalkane by reacting phenols with ketone and isoalkenylphenol in the presence of acid catalyst the improvement comprising(a) removing phenol from said mother liquor by distillation, combining the bottoms thus obtained with a basic catalyst and continuously decomposing the combination in a reactive rectification stage into (i) phenol and isoalkenylphenol which pass overhead as the distillate, and (ii) bottoms, and(b) mixing said bottoms with an acid catalyst, continuously introducing the resulting mixture into a second reactive rectification stage to cause the decomposition of the mixture into (i) phenol and (ii) discarded bottoms, and(c) returning the phenol and isoalkenylphenol from stages (a) and (b) to said process.