Preparation method of high-purity L-nicotine medical intermediate

Abstract

The invention discloses a preparation method of a high-purity L-nicotine medical intermediate, which comprises the following steps: synthesis of myosmin: pumping dry xylene into a condensation reaction kettle, adding metal sodium and tert-butyl alcohol, heating, preserving heat, and cooling for later use; the method comprises the following steps: pumping xylene, ethyl nicotinate and N-vinylpyrrolidone into a reaction kettle, carrying out heat preservation, carrying out stirring until the solution is clear, and pumping the solution into a high position; dropwise adding the high-order reaction liquid into a condensation reaction kettle, heating after dropwise adding, and cooling for later use; adding concentrated hydrochloric acid and water into an acidolysis kettle, stirring and cooling, transferring a reaction solution in the condensation reaction kettle into the acidolysis kettle, transferring a layered lower water layer into a reflux kettle for reflux, transferring into a desolventizing kettle, transferring a desolventizing kettle bottom solution into a myosmin distillation kettle, and distilling off myosmin under reduced pressure; and preparing the L-nicotine. By adopting the preparation method of the high-purity L-nicotine medical intermediate, the high-purity L-nicotine is obtained, the consumption of acid, alkali and organic matters is reduced, and the cost is greatly reduced.

Description

technical field [0001] The invention relates to the technical field of nicotine preparation, in particular to a preparation method of a high-purity L-nicotine pharmaceutical intermediate. Background technique [0002] Nicotine, also known as nicotine, is an alkaloid found in plants of the nightshade family (Solanum) and an important component of tobacco. Traditional nicotine is mainly extracted from tobacco leaves, but the purity is low, and many impurities cannot be purified, so that the nicotine extracted from plants cannot meet the market demand. [0003] For nicotine, it is often closely associated with "death" and "cancer", but more and more studies have shown that nicotine in cigarettes is not as serious as imagined, and the real carcinogen is mainly tar. There are also harmful substances such as aromatic hydrocarbons, methanol and carbon monoxide, which are produced by the combustion of tobacco leaves. [0004] Although the dangers of smoking are recognized worldwid...

AI Technical Summary

Problems solved by technology

[0013] (1) Use sodium hydride and potassium cyanide as catalysts because of their poor nucleophilicity, high reaction temperature, and long reaction time, which can easily lead to the polymerization of N-vinylpyrrolidone. If you want to react completely, you must increase the amount of alkali and N-vinylpyrrolidone , resulting in increased side reactions and increased acid-base dosage

[0014] (2) Sodium tert-butoxide or potassium tert-butoxide is used as alkali because of its strong water absorption, it is easy to deteriorate, and the feeding dust is relatively large, which is prone to spontaneous combustion hazards and has high environmental requirements.

[0015] (3) Catalyzed hydrogenation reduction with palladium carbon or methylation after reduction with sodium borohydride can only obtain swollen nicotine, and nicotine must be resolved. The price of the resolving agent L-dibenzoyl tartaric acid is relatively high Expensive, difficult to recycle, and the efficiency of splitting is low, and the steps are cumbersome

[0016] (4) The reaction yield of the original process is low, there are many side reactions, the amount of acid and alkali is large, and the difficulty of raw material recovery leads to high cost of synthetic nicotine

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