Hydrochloric Acid → 4,4'-Dihydroxybiphenyl

Participants

Reaction Conditions

Reaction Steps

400 g (6.1 moles) of potassium hydroxide having a water content of 15% by weight and 40 g (0.38 mole) of sodium carbonate were initially taken in a stirred 1 1 V2A stainless steel kettle and 195 g (0.5 mole) of the dipotassium salt of biphenyl-4,4'-disulfonic acid were introduced at 280° C. The temperature was then increased to 320° C., this temperature was maintained for 3 hours and the melt was cooled by constantly metering in water and simultaneously reducing the heating bath temperature. The reaction mixture was diluted with water and acidified with concentrated hydrochloric acid at 90° C. to a pH of 6.5. The resulting precipitate was filtered off under suction, and 4,4'-dihydroxybiphenyl was extracted by means of acetone. The extracting agent was removed to give 85.5 g (92%) of 4,4'-dihydroxybiphenyl, which had a purity of >99% (HPLC).

Provenance & Evidence