The invention discloses a novel catalytic process method for 2, 5-dimethoxy-4-chloracetylacetanilide, and belongs to the field of
chemical synthesis. The preparation method comprises the following steps: mixing 2, 5-dimethoxy-4-chloroaniline, an
ionic liquid catalyst, a reaction mother solution and
diketene, reacting for 1-1.5 hours at the
reaction temperature of 10-20 DEG C, and cooling, filtering and
drying after the reaction is completed to obtain a finished product. According to the invention, 2, 5-dimethoxy-4-chloroaniline and
diketene are taken as raw materials, one-step synthesis is carried out by adopting
acylation reaction catalyzed by the
ionic liquid, the target product selectivity is high, and
pollution is less during post-treatment; due to the introduction of the
ionic liquid catalyst, the electrophilicity of the aromatic ring compound is improved, the reaction is easier to carry out, and the ionic liquid catalyst is green, non-toxic, recyclable and easy for industrial production; and the
mother liquor can be continuously used as an indiscriminate
mother liquor for next reaction.