Method for preparing chlorotoluene

Abstract

The invention relates to a method of toluene chlorination reaction and particularly relates to a method for preparing chlorotoluene through the toluene chlorination reaction. The method is characterized by adopting a made-to-order macroporous metal chelating resin as a catalyst; and the catalyst is chelated from an iron chloride water solution with the mass concentration of 10% and D418 styrene cation exchange resin with the particle size of 0.5-1.5 millimeters and the aperture of 0.6-1 nanometer at 60 DEG C under the conditions of stirring and ph of 3.5. Thus, electrophilic reaction during toluene chlorination is mainly carried out in a catalyst pore path; because chlorotoluene is smaller than o-chlorotoluene in molecular dimension and has higher diffusion velocity than o-chlorotoluene in a pore path with certain size, more para-position products are obtained; in addition, the method disclosed by the invention has low requirements on temperature and pressure; and the highest content ratio of chlorotoluene to o-chlorotoluene is 4.1:1 under the conditions of 10-80 DEG C and 0.05-0.1 MPa.

Description

technical field

[0001] The invention relates to a method for ring chlorination of toluene, in particular to a method for preparing p-chlorotoluene through ring chlorination of toluene. Background technique

[0002] Toluene reacts with chlorine gas in the liquid phase under the action of Lewis acid catalysts such as iron trichloride, antimony trichloride, aluminum trichloride, etc., and the mono-substituted aromatic ring product monochlorotoluene is the mixture of o-chlorotoluene and p-chlorotoluene. mixture. If ferric chloride is used as catalyst, the ratio of p-chlorotoluene to o-chlorotoluene in the monochlorotoluene mixture is about 0.5-0.55:1.

[0003] Among the toluene ring chlorination products, p-chlorotoluene is an important intermediate in the production of fine chemical products such as pesticides, medicines, and dyes, while o-chlorotoluene has much smaller uses, and a large part of it is used as a low-priced solvent.

[0004] For a long time, people have been tr...