Preparation method of high-purity racemic nicotine

Abstract

The invention relates to a preparation method of high-purity racemic nicotine, which comprises the following steps: (1) reacting 4-(pyridine-3-yl)-1-butyraldehyde, a strong acid catalyst and 2, 2-dimethoxypropane to obtain a product 3-(4, 4-dimethoxybutyl) pyridine; (2) reacting and oxidizing the 3-(4, 4-dimethoxybutyl) pyridine obtained in the step (1) with an oxidizing agent to obtain a product 4, 4-dimethoxy-1-(pyridine-3-yl) butanone; and (3) dissolving the 4, 4-dimethoxy-1-(pyridine-3-yl) butanone obtained in the step (2) in an organic solvent, reacting under an acidic condition, concentrating under reduced pressure, adding methylamine hydrochloride and a reducing agent, reacting to obtain a racemic nicotine crude product, and refining to obtain the pure racemic nicotine. The method for preparing the racemic nicotine is simple in process, mild in reaction condition, free of gas emission in the reaction process, environment-friendly and high in yield, and is an industrial method which is expected to synthesize the racemic nicotine on a large scale.

Description

Technical field: [0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a preparation method of high-purity racemic nicotine. Background technique: [0002] Nicotine replacement therapy (NRT) usually refers to providing nicotine to ex-smokers through different delivery forms. The core of related products is to reduce the withdrawal reaction of ex-smokers, so as to gradually get rid of their dependence on burning cigarettes. [0003] As a typical representative of nicotine replacement therapy, new tobacco includes two main forms: heat-not-burn and atomization. In recent years, the new tobacco industry has developed rapidly, and nicotine, as the core functional ingredient of the new tobacco industry, has an increasing consumption and demand. [0004] At present, most of the nicotine circulating on the market is extracted from tobacco, which also causes it to be seriously affected by external factors such as the output of tobacco...

AI Technical Summary

Problems solved by technology

[0022] However, this route actually uses expensive DCC as a carboxyl activator, which is not suitable for large-scale industrial production, and the Grignard reagent is used in the second conversion process, which requires strict anhydrous and oxygen-free control of the heat of reaction. Excess Grignard reagent needs to be quenched with a large amount of saturated aqueous ammonium chloride

The solid acid catalysts used in this route are weak acid ICR-50 and strong acid Amberlyst15 cation exchange resin respectively, and the amount of catalytic reaction substrate is small, which cannot meet the needs of large-scale production

[0023] In short, the route for synthesizing racemic nicotine in the above-mentioned prior art is either expensive in raw materials, cumbersome in steps, long in production cycle, unsatisfactory in yield or purity, or has reagents that are controlled reagents and has potential safety hazards, so it is difficult to apply industrialized mass production

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