Hydrochloric Acid → 5,5-Bis(4-hydroxyphenyl)hydantoin

Participants

Reaction Steps

100 Grams of 4,4'-dihydroxybenzophenone, 152.1 g of potassium cyanide and 426.3 g of ammonium carbonate were heated to 120° C. together with 750 ml. of formamide and 150 ml. of water with stirring in an autoclave for 48 hours. The reaction liquid was made acidic with concentrated hydrochloric acid, mixed with water and allowed to stand overnight. The precipitates thus formed were filtered out. The precipitates were decolorized by active carbon and recrystallized from 50% methanol to obtain 111.4 g of 5,5-bis(4-hydroxyphenyl)hydantoin in the form of white crystals.

Provenance & Evidence