Method for preparing trifluoromethyl aromatic compound

A method for preparing a trifluoromethyl aromatic compound, comprising:

• mixing a trichloromethyl aromatic compound with an organic alkali hydrofluoride to obtain a mixture, and subjecting the mixture to fluorination to obtain a reaction solution, wherein a molar ratio of the trichloromethyl aromatic compound to the organic alkali hydrofluoride is in a range of 1:
• (1-3);
• subjecting the reaction solution to solid-liquid separation to obtain an organic alkali hydrochloride wet product and a filtrate, drying the organic alkali hydrochloride wet product, and condensing and recycling a gas generated during the drying to obtain a condensed product;
• and
• purifying the filtrate and the condensed product by rectification to obtain the trifluoromethyl aromatic compound;
• wherein the trichloromethyl aromatic compound comprises one selected from the group consisting of a trichloromethyl benzene compound and a trichloromethyl pyridine compound:
• the trichloromethyl benzene compound has a structure as shown in Formula I;
• and the trichloromethyl pyridine compound has a structure as shown in Formula II;
• wherein
• in Formula I:
• R1 is halogen and R2 is —NO2;
• and in Formula II:
• R is halogen;
• and
• under the condition that a pot residue obtained from the rectification comprises one or more selected from the group consisting of the trichloromethyl aromatic compound, a monofluoro substitute and a difluoro substitute thereof, the method further comprising:
• returning the pot residue obtained from the rectification to the fluorination for reuse.