Purification method of isoquinoline

Abstract

The invention provides a new purification method of isoquinoline, and the purified isoquinoline has high purity and low impurity and can meet the requirement of various mechanical manufacture, in order to reach the goal, the technical scheme of the invention comprises: 1) performing acid-cleaning and alkalic-cleaning to wash oil (one distillate of coal tar) to obtain rough quinoline distillate and then performing rectification to obtain distillate containing 85 to 90 percent of isoquinoline, 2) taking the distillate containing 85 to 90 percent of isoquinoline as starting material, after crystallizing by cooling and melting by heating up, cutting the distillate into a plurality of distillates when heating up, performing N sections of the repeated operation of cooling and melting by heating up on the end distillate in the plurality of distillates to obtain isoquinoline with the purity of larger than or equal to 99 percent. The invention has the benefits that the technology is relatively simple, the cost is low, the purity of isoquinoline of the obtained product is larger than or equal to 99 percent, the impurity content is low, the method can meet the requirement of mechanical manufacture, and effectively reduces the production cost.

Description

【Technical field】 [0001] The invention relates to a purification method in the chemical field, in particular to a purification method of isoquinoline with high purity and low cost. 【Background technique】 [0002] Present many pharmaceutical intermediates such as producing octahydroisoquinoline etc. (a kind of pharmaceutical intermediate, reaction formula is as follows) all use raw material: isoquinoline, in the production process of above-mentioned octahydroisoquinoline, hydrogenation catalyst is to A variety of trace impurities in the isoquinoline raw material are very sensitive. In severe cases, the hydrogenation catalyst will be poisoned and lose its catalytic function, resulting in production failure. Therefore, the purity of isoquinoline and the content of impurities are very strict in this reaction. A high purity isoquinoline material with low impurity content must be used. [0003] [0004] However, isoquinoline with high purity and low impurity content is very di...

AI Technical Summary

Problems solved by technology

Although this method does not have high requirements for raw materials, the purity of the obtained product is not high and the impurity content in the product is not significantly reduced, which cannot meet the needs of pharmaceutical production.

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