Synthesis
Benzanthrone is prepared commercially by reacting
anthraquinone with glycerol, sulfuric acid,
and a reducing agent, usually iron. This involves
reduction of anthraquinone to anthrone
(122), which condenses immediately with the
acrolein formed by dehydration of glycerol, and
is finally oxidized by the sulfuric acid , , . An improved process is described
in , . More recently, the use of phosphorus or a phosphorus compound, e.g., sodium
hypophosphite, has been proposed as the reducing
agent . Electrochemical procedures
have been also suggested , . It is possible
to start with anthrone prepared in a separate
step, e.g., by hydrogenation . Benzanthrone
is best purified by sublimation.
