A mixture of 20 g (80 mmol) of 2,4-dihydroxy-4'-chlorobenzophenone, 21.9 g (88 mmol) of 1-bromododecane and 8.4 g (100 mmol) of sodium hydrogen carbonate in 77.6 g of sec-butyl alcohol and 25.6 g of H2O is heated with stirring and maintained at reflux for 20 h. The reaction mixture is stirred for an additional 15 min in the presence of 0.8 g of activated charcoal and is then filtered while hot. After the filtrate has cooled, the product crystallizes. It is recrystallized from sec-butyl alcohol to give 21.5 g of pale yellow crystals having a melting point of 61°-63° C.
