Method for preparing 3,5-dimethylpyridine-N-oxide

Abstract

The invention discloses a method for preparing 3,5-dimethylpyridine-N-oxide, and the method comprises the following steps: using oxidant to oxidize 3,5-dimethylpyridine and then purifying the reacted solution to obtain the product, 3,5-dimethylpyridine-N-oxide. In the method of the invention, the purity of the product is high, the preparation method is simple, no solvent is needed, the cost is low, and the method is environmentally friendly and is applicable to industrial continuous production.

Description

technical field The invention belongs to the field of chemical pharmacy, and in particular relates to a method for preparing 3,5-lutidine-N-oxide directly from 3,5-lutidine by oxidation with an oxidizing agent. Background technique 3,5-Lutidine is an important raw material for organic synthesis. The introduction of N-oxide group on the pyridine ring can improve its nitration reaction ability and change the attack direction of nitro group. Since a considerable part of the negative charge of oxygen in the N-oxide pyridine molecule returns to the pyridine ring through the conjugation effect, forming p-π conjugation, it is activated, and the nitro group is mainly on the 2-position of the N-oxide pyridine ring and 4-bit. At the same time, the nitro group on the N-oxidized pyridine nitrated derivative is easy to be substituted by nucleophiles, and the alkyl group on the ring carbon is also easy to react with aldehydes, even less active aldehydes, and alkylation, acylation or acid...

AI Technical Summary

Problems solved by technology

However, the price of metal oxide catalysts is relatively high, and the catalyst will be lost during the catalytic oxidation process. When recovering these metal oxide catalysts, they need to be vulcanized, and their active metal components are converted from an oxidized state to a sulfurized state before they have good hydrogenation activity. and activity stability; or direct incineration, which is more harmful to the environment, and part of the catalyst will be dissolved in the organic phase of the extraction of picoline-N-oxide during post-treatment, and the catalyst cannot be mixed with picoline-N-oxide The separation is thorough, which affects the purity and quality of the product pyridine-N-oxide

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