Synthesis process for o-chlorobenzaldehyde

Abstract

The invention discloses a synthesis process of o-chlorobenzaldehyde. The synthesis process of o-chlorobenzaldehyde comprises the following steps: feeding chlorine in o-chlorotoluene, carrying out catalytic chlorination under the condition of illumination to obtain chlorination liquid, wherein the ratio of the amount of the chlorine to the amount of the o-chlorotoluene is 2-4: 1, the reaction time is 1-2 hours, and the reaction temperature is 100-120 DEG C; distilling the chlorination liquid under reduced pressure, and separating out chlorobenzyl chloride and the o-chlorotoluene to obtain mixed liquid of o-chlorobenzyl dichloride and o-chlorobenzyl trichloride; carrying out hydrolysis reaction on the mixed liquid by using ferric chloride and zinc chloride as catalysts to obtain hydrolysate, wherein the temperature of hydrolysis reaction is 100-120 DEG C, a solvent is water, and the reaction time is 1.5-3 h; and carrying out rectification and purification on the hydrolysate in a vacuum state to obtain o-chlorobenzaldehyde. According to the technical scheme, the cost is further reduced, and the quality of the product is improved. Reasonable catalytic conditions are adopted, the synthesis process is a perfect greening technological synthesis method, generation of by-products is controlled effectively, and the quality of the product is improved further.

Description

technical field

[0001] The present invention relates to the synthesis technique of benzaldehyde, in particular to the synthesis technique of o-chlorobenzaldehyde. Background technique

[0002] O-chlorobenzaldehyde is an important intermediate in organic synthesis, mainly used in the manufacture of o-chlorobenzaldehyde, o-chlorobenzyl chloride and cloxacillin sodium as the main raw material for pharmaceuticals, and is also widely used in the manufacture of pesticides The raw material of high-efficiency acaricide products has a large market demand.

[0003] The synthesis methods of o-chlorobenzaldehyde include chlorination hydrolysis, direct oxidation and indirect oxidation, the most common in industry is the chlorination hydrolysis. The classic chlorination hydrolysis process is to chlorinate o-chlorotoluene into o-chlorobenzyl chloride and then catalyze the hydrolysis to o-chlorobenzaldehyde. However, in addition to 80% o-chlorodichlorobenzyl, there are about 20% o-chlorobe...