Preparation method of quinoline, isoquinoline and various kinds of methyl quinoline

Abstract

The invention discloses a preparation method of quinoline, isoquinoline and various kinds of methyl quinoline. The preparation method specifically comprises the following steps: (1) dissolving thiourea in water to form a thiourea solution; (2) uniformly mixing isoquinoline residual liquid with the thiourea solution, carrying out reactions under stirring, and after reactions, filtering and drying to obtain a white solid product; (3) preparing a mixed solvent from methanol, propanol, butanone and pentanone, adding the white solid product into the mixed solvent, uniformly stirring, and filteringto respectively obtain a filtrate and a thiourea crown inclusion compound; (4) subjecting the filtrate to cooling crystallization and separation to obtain 2,4-dimethylquinoline, and (5) putting the thiourea crown inclusion compound into a crystallization reaction kettle, and carrying out fractional crystallization to respectively obtain isoquinoline, 3-methylquinoline, 4-methylquinoline, 2-methylquinoline and quinoline. The disclosed preparation method is short in technological process, high in raw material utilization rate and low in production cost, and does not damage the environment.

Description

technical field [0001] The invention belongs to the field of petrochemical industry, and in particular relates to a method for preparing quinoline, isoquinoline and various methylquinolines. Background technique [0002] At present, quinoline, isoquinoline and a variety of methylquinolines are widely used in medicine, and new drugs have been developed continuously, including antimalarial drugs, local anesthetic drugs, antibacterial and fungal drugs, antitumor and Infectious disease drugs; and quinoline, isoquinoline and a variety of methylquinolines are also widely used in agriculture, such as herbicides, fungicides, insecticides, etc., which are not only effective but also have low toxicity and residue; in addition , Quinoline, isoquinoline and methyl quinoline can also be used as rubber anti-aging agent, photographic sensitizer, metal anti-corrosion agent, etc. [0003] However, the existing production processes of quinoline, isoquinoline and methylquinoline have the prob...

AI Technical Summary

Problems solved by technology

[0003] However, the existing production processes of quinoline, isoquinoline and methylquinoline have the problem of difficult separation, which leads to low utilization rate of raw materials, complicated production process and high production cost

As disclosed in the patent document (200910200498.5), the fractional crystallization method is used to purify isoquinoline, which can obtain high-purity isoquinoline, but the preparation process is complicated, the production cost is high, and the purified waste is not recycled and utilized. Cause waste of resources; In addition, as disclosed in the patent document (201110332077.5), adopt the urea inclusion method to separate and obtain 2-methylquinoline, wherein although 2-methylquinoline is obtained, the raw material is required to be distilled 2-methylquinoline Quinoline, the purity is greater than 50%, and the preparation process is complicated; as disclosed in the patent document (201110332052.5), the solvent and reaction crystallization method is used to separate 1-methylquinoline, but the raw material utilization rate is low, and waste acid water will be produced, which is harmful to the environment Cause damage; the patent document (201310044393.1) discloses the use of solvent distillation and sulfuric acid reaction crystallization to extract 6-methylquinoline, but its extraction process is long, resulting in waste acid water and polluting the environment

[0004] Therefore, it is an urgent problem for those skilled in the art to provide a method for preparing quinoline, isoquinoline and multiple methylquinolines to solve the problems of long process flow, low raw material utilization rate and environmental pollution.