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Method for preparing tetramethyl pyrazine

A technology of ligustrazine and oxidant, applied in the direction of organic chemistry, can solve the problems of easy volatilization, high production cost, and large consumption of organic solvents, and achieve the effects of small organic residues, low production cost, high yield and reliability

Inactive Publication Date: 2007-03-28
张锋
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The extraction process of the above-mentioned ligustrazine is cumbersome, time-consuming, and consumes a large amount of organic solvents, leaving a large amount of organic solvents in the discharge, causing great environmental pollution.
Because ligustrazine has a low melting point and is easy to volatilize, atmospheric distillation will also distill out with water vapor, so the production cost is high and the yield is low

Method used

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  • Method for preparing tetramethyl pyrazine
  • Method for preparing tetramethyl pyrazine
  • Method for preparing tetramethyl pyrazine

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Add 50g of 0.57mol of 3-hydroxy-2-butanone, 150ml of ethanol and 35.78g of 0.54mol of ammonium acetate into a 500ml round-bottomed flask, feed nitrogen, heat the oil bath at 79-89°C, and stir for 5-8 hours with magnetic force . After the stirring was completed, it was left open or magnetically stirred under oxygen condition for 12 hours. Add 31.45g of 0.36mol manganese dioxide, and stir magnetically for 1 to 2 hours. After the reaction is complete, use a Buchner funnel to filter the remaining manganese dioxide under reduced pressure. Under reduced pressure distillation, 29.12 g of ligustrazine needle crystals were collected by vacuum distillation. Use 50ml of ethyl acetate and 6 grams of activated carbon to re-distill under reduced pressure. The conditions of the reduced-pressure distillation are the same as those mentioned above. After drying, 28.32 g of 0.21 mol of Ligustrazine was received, with a yield of 72.50%.

[0026] Using 3-hydroxy-2-butanone and ammonium ac...

Embodiment 2

[0032] In the present invention, ketones such as butanone can be halogenated under acidic conditions to obtain acetoin, and then the method of Example 1 can be used to prepare ligustrazine. The specific method is: take 50g of butanone in a 250ml three-necked flask (equipped with a stirrer and a thermometer), add 80ml of hydrochloric acid and 120g of liquid bromine, stir, and heat to 50°C to 60°C with nitrogen gas for 2 to 3 minutes. hour, then alkalized with sodium hydroxide to obtain the acetoin mixture, passed through n-hexane for extraction, and dehydrated with anhydrous sodium sulfate to obtain acetoin, which was transferred to a flask, and Ligustrazine was prepared by the method of Example 1.

[0033]

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Abstract

The invention relates to a Chuanxiongzine preparing method, comprising the steps of: using 3-hydrox-2-butanone and ammonium acetate as raw materials, adding in alcohol, charging nitrogen gas, and blending in hot bath for 5-8 h; on air or oxygen condition, blending for 12 h; adding in oxidant, and blending for 1-2 h, where the weight ratio of oxidant to 3-hydrox-2-butanone = (0.5-1):1; and filtering out the remaining oxidant; vacuum-distilling to make it. And the method has high yield. And the organic solvent utilization in the preparing course is less, beneficial to environmental protection. And the invention has advantages of low cost and simple operation.

Description

technical field [0001] The invention relates to a preparation method of medicine, in particular to a preparation method of tetramethylpyrazine with high yield. Background technique [0002] Ligustrazine (Ligustrazine) is a kind of alkaloid monomer isolated and purified from the rhizomes of Umbelliferae plants, and its chemical name is: 2,3,5,6-tetramethylpyrazine, referred to as tetramethyl Pyrazine (Tetramethyl Pyrazine TMP). It has antihypertensive and blood vessel expansion thrombolytic effects, and is mainly used clinically to treat ischemic cardiovascular and cerebrovascular diseases, such as cardiovascular and cerebrovascular diseases, cerebral embolism, coronary heart disease, angina pectoris, vasculitis, chronic pulmonary heart disease, chronic renal failure Wait. In recent years, it has been found that it has the effect of blocking calcium ion, and has the effect of chemotherapy sensitization and reversal of multidrug resistance of tumor cells. [0003] Ligustraz...

Claims

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Application Information

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IPC IPC(8): C07D241/12
Inventor 张锋
Owner 张锋
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