A method for chlorinating blue anthrone, violanthrone or isoviolanthrone is provided. Reaction is carried out with a chlorinating agent (any one of sulfonyl chloride, thionyl chloride and triphosgene) in a reaction solvent (a Lewis acid ionic liquid with anions being of a transition metal halide) for 2 h to 40 h at a chlorination temperature not lower than room temperature and not higher than 120° C.; and then the reaction product is subjected to post-treatment to obtain a target product. The present disclosure cuts off a generation route of harmful substances such as dioxins and their derivatives from the source. There are no dioxins or similar substances generated in the product, and the reaction has high atomic utilization rate and low energy consumption, which fills the gap in the field of chemical technologies at home and abroad.

A method for chlorinating blue anthrone, violanthrone or isoviolanthrone is provided. Reaction is carried out with a chlorinating agent (any one of sulfonyl chloride, thionyl chloride and triphosgene) in a reaction solvent (a Lewis acid ionic liquid with anions being of a transition metal halide) for 2 h to 40 h at a chlorination temperature not lower than room temperature and not higher than 120? C.; and then the reaction product is subjected to post-treatment to obtain a target product. The present disclosure cuts off a generation route of harmful substances such as dioxins and their derivatives from the source. There are no dioxins or similar substances generated in the product, and the reaction has high atomic utilization rate and low energy consumption, which fills the gap in the field of chemical technologies at home and abroad.