Method for cleanly preparing high-purity pyridine hydrochloride

A kind of technology of pyridine hydrochloride and pyridine, which is applied in the field of pyridine hydrochloride to achieve the effects of cost reduction, improvement of purity and yield, and simplification of steps

Active Publication Date: 2014-04-30
济宁中再生华惠医药科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0010] In order to solve the problems of poor quality of the above pyridine hydrochloride products, high cost, large energy consumption and difficult disposal of waste liquid in the preparation process, the present invention provides a A method for the clean preparation of high-purity pyridine hydrochloride with low cost in the preparation process, good quality, easy control of reaction conditions, and easy disposal of waste liquid

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0042] A method for cleaning and preparing pyridine hydrochloride, comprising the following steps:

[0043] (1) Dissolve pyridine in toluene to obtain a mixed solution, wherein the volume ratio of pyridine to toluene is 1:5;

[0044] (2) Add 98% concentrated sulfuric acid to the glass-lined reactor, drop 31% hydrochloric acid to generate hydrogen chloride gas, and the weight ratio of hydrochloric acid to concentrated sulfuric acid is 1:2.5;

[0045] (3) The hydrogen chloride gas produced in step (2) is dried with concentrated sulfuric acid, passed through the buffer tank, and passed into the mixed solution in step (1). The molar ratio of hydrogen chloride to pyridine in the mixed solution is 1:1.05. React at a temperature of -35°C, the pressure in the kettle is 0.01-0.02MPa, filter, and continue to add pyridine to react after the filtrate is recovered, and repeat recycling. The filter cake is vacuum-dried at a temperature of 50-55°C and a vacuum of -0.090-0.092 MPa, the recov...

Embodiment 2

[0048] A method for cleaning and preparing pyridine hydrochloride, comprising the following steps:

[0049] (1) Dissolve pyridine in toluene to obtain a mixed solution, wherein the volume ratio of pyridine to toluene is 1:7;

[0050] (2) In the glass-lined reactor, add 98% concentrated sulfuric acid to it, and drop 31% hydrochloric acid to generate hydrogen chloride gas, wherein the weight ratio of hydrochloric acid to concentrated sulfuric acid is 1: 3.5;

[0051] (3) The hydrogen chloride gas produced in step (2) is dried with concentrated sulfuric acid, passed through the buffer tank, and passed into the mixed solution in step (1). The molar ratio of hydrogen chloride to pyridine in the mixed solution is 1: 1.1. React at a temperature of -45°C, the pressure in the kettle is 0.01-0.02MPa, filter, and continue to add pyridine to react after the filtrate is recovered, for repeated recycling. The filter cake is vacuum-dried at a temperature of 50-55°C and a vacuum degree of -0.09...

Embodiment 3

[0053] A method for cleaning and preparing pyridine hydrochloride, comprising the following steps:

[0054] (1) Dissolve pyridine in toluene to obtain a mixed solution, wherein the volume ratio of pyridine to toluene is 1:6;

[0055] (2) In the glass-lined reactor, add 98% concentrated sulfuric acid to it, and drop 31% hydrochloric acid to generate hydrogen chloride gas, wherein the weight ratio of hydrochloric acid to concentrated sulfuric acid is 1:3;

[0056] (3) The hydrogen chloride gas produced in step (2) is dried with concentrated sulfuric acid, passed through the buffer tank, and passed into the mixed solution in step (1). The molar ratio of hydrogen chloride to pyridine in the mixed solution is 1: 1.1. React at a temperature of -40°C, the pressure in the kettle is 0.01-0.02MPa, filter, and continue to add pyridine to react after the filtrate is recovered, and repeat recycling. The filter cake is vacuum-dried at a temperature of 50-55°C and a vacuum degree of -0.090-0...

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Abstract

The invention relates to the technical field of pyridine hydrochloride and particularly relates to a method for cleanly preparing high-purity pyridine hydrochloride. The method comprises the following steps: dissolving pyridine by using an organic solvent to obtain a mixed solution; adding 98% concentrated sulfuric acid into a container and dripping 31% hydrochloric acid into the container to generate hydrogen chloride gas, wherein the weight ratio of hydrochloric acid to concentrated sulfuric acid is 1:(2.5-3.5); introducing the hydrogen chloride gas into the mixed solution to react; filtering to obtain filtering dreg, namely pyridine hydrochloride. According to the method, the hydrogen chloride gas with low price is prepared by taking concentrated sulfuric acid and hydrochloric acid as the raw materials; after being dried by concentrated sulfuric acid, the hydrogen chloride gas is used for a production process, the chemically-pure quality of the gas stored in a steel bottle is reached and the cost is reduced by 70%; prepared pyridine hydrochloride has a white appearance, the yield is more than 98%, the purity is up to 99.5% and the water content is less than 0.2%; the quality of pyridine hydrochloride stays ahead of that of domestic products; the byproduct sulfuric acid is used for producing magnesium sulfate heptahydrate; the application is wide; the whole production process has no emission of three wastes and is clean and environment-friendly.

Description

technical field [0001] The invention relates to the technical field of pyridine hydrochloride, in particular to a method for cleanly preparing high-purity pyridine hydrochloride. Background technique [0002] Pyridine hydrochloride, also known as pyridine hydrochloride, CAS No. 628-13-7, molecular formula C 5 h 5 N·HCl, relative molecular mass: 115.56. Pyridinium hydrochloride is a white crystal with a melting point of 144-146°C. Miscible with water, ethanol and other organic solvents, insoluble in acetone, ether, carbon tetrachloride and aromatics. This product is very easy to absorb moisture, and the solubility of pyridine hydrochloride in water at normal temperature is 560g / 100g water. [0003] High-purity pyridine hydrochloride is an important pharmaceutical intermediate, mainly used in the production of clarithromycin, a macrolide antibiotic. Clarithromycin, also known as clarithromycin, is a derivative of erythromycin. It was successfully developed by Japan's Ta...

Claims

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Application Information

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Patent Type & AuthorityApplications(China)
IPC IPC(8): C07D213/18C07D213/127C01F5/40
CPCC07D213/127C07D213/18
Inventor林存符樊庆华苏广武刘茂先郑关伟
Owner济宁中再生华惠医药科技有限公司