反应详情

New catalysts which promote selectively the α-sulfonation of anthraquinone in liquid sulfur dioxide as a solvent are taught addressed in, "Palladium-Catalyzed α-Monosulfonation of Anthraquinone by Sulfur Trioxide in Liquid Sulfur Dioxide" by Yasuziro Kawabata, et al., appearing in Journal of the Chemical Society of Japan, 1980, (3), p. 322-326, wherein the use of liquid sulfur dioxide and palladium containing compounds in the sulfonation reaction resulted in about 100% conversion of anthraquinone and 76% yield of 1-anthraquinonesulfonic acid with 99% α-selectivity. Further, Kawabata, et al. disclose a process of reprecipitation of the solubilized palladium on carbon by hydrogen treating, in which the pH value of the reaction mixture was adjusted to >7, and then 20 atm hydrogen was introduced to deposit the solubilized Pd on carbon. However, the conversion of anthraquinone was found to have decreased to 70% as the recovered Pd-carbon was recycled. Additionally, air or oxygen was introduced into the mixture after the Pd-carbon had been removed in order to precipitate a salt of the monoanthraquinonesulfonic acid.