Synthesis of pyridine-N-oxide

Abstract

Synthesis of pyridine-N-oxide is carried out by preparing sodium tungstate into carrier phosphate-tungstic acid by wetting method, vacuum drying to generate anhydrous product, putting anhydrous product and carrier into container, formulating solution by deionized water, agitating to remove water content, drying at high-temperature, activating to obtain catalyst, putting catalyst and pyridine into flask, oxidation reacting by hydrogen peroxide, filtering out catalyst and decompress distilling to obtain the final product. It's simple, fast and cheap and has less solvent.

Description

Technical field: [0001] The invention belongs to a process for organic synthesis intermediates, in particular to a process for synthesizing pyridine-N-oxide. Background technique: [0002] Pyridine-N-oxide is an important organic synthesis intermediate, widely used in various industries such as medicine, dyeing, catalyst, etc., such as the synthesis of antibiotics Cephaopirin and 4-substituted pyridine derivatives . In addition, it is also a new type of non-ionic surfactant, which can increase the adsorption surface and stabilize the foam. [0003] The synthetic method of traditional pyridine N-oxide has the following several: 1, peracetic acid oxidation method: add dropwise 40% peracetic acid in pyridine solution under stirring, then process to obtain product. 2. Add pyridine to glacial acetic acid, add dropwise 35% hydrogen peroxide, and then process to obtain the finished product. 3. Oxidation of pyridine with phthalic acid peroxide. 4. Oxidation of pyridine with sodi...

AI Technical Summary

Problems solved by technology

[0004] At present, the first and second methods are often used, which use a large amount of glacial acetic acid, consume a lot of solvent, are not easy to recover, and need to be neutralized and extracted, and the reaction cycle is very long

Although the third and fourth methods avoid the use of a large amount of solvents, the price of the raw material itself is very high, and the post-processing is very difficult, so this method is basically not used

Although the fifth method has a short reaction cycle and does not have a large amount of solvent, the cost is high because the catalyst is inconvenient to recover and expensive