Di:phenoxy-anthraquinone prodn. from di:nitro cpd. - and alkali phenoxide, using alkylbenzene as solvent

摘要

Prodn. of 1.5- and 1,8-diphenoxyanthraquinone (I) comprises reacting 1,5- or 1,8-diphenoxyanthraquinone (II) with alkali phenoxide in presence of a monoalkylbenzene as inert, water-immiscible solvent. The solvent is pref. toluene or esp. ethylbenzene and 1.75-8.7 wt. pts. are used per wt. pt. (II). The phenoxide is pref.2-2.5 moles per mole (II) and reaction is esp. at 70-170 degrees C. The reaction mixt. is pref. worked up by steam or vacuum distillation to remove solvent, then any nitrite is pref. destroyed with amidosulphonic acid. (I) are intermediates for blue polyester dyes. They are prepd. in 90-95% yield and 92-97% purity and the solvents used are less toxic and more readily biodegradable than conventional solvents.