Use of bismuth nitrate and iron nitrate as nitrification agent in aromatic compound nitrification

Abstract

Use of bismuth nitrate and ferric nitrate in aromatic substance nitrating reaction as nitrating agent and its method are disclosed.

Description

technical field [0001] The invention relates to the application of bismuth nitrate and / or iron nitrate as a nitrating agent in the nitration reaction of aromatic compounds. Background technique [0002] The nitration reaction of aromatic compounds is an important class of organic synthesis reactions. The classic industrial nitration reaction method is the mixed acid method, that is, under the catalysis of concentrated sulfuric acid, the nitration reaction is carried out with concentrated nitric acid as the nitrating reagent. This traditional synthesis method has many side reactions, low selectivity, high requirements for reaction equipment, and serious environmental pollution. Therefore, exploring novel green nitration reactions of aromatic compounds is still a research hotspot. [0003] In recent years, people have developed some new nitrification methods. [0004] For example, A.V.Joshi et al. reported that using 4-substituted phenol as a substrate and 6-15wt% dilute ni...

AI Technical Summary

Problems solved by technology

The nitrating reagent can carry out nitration reaction to aromatic compounds in the presence of a large amount of acetic anhydride in carbon tetrachloride solution, for example, when phenol is used as a substrate, the selectivity of o-nitrophenol is as high as 86%, while that of p-nitrophenol Only 6%, it is a highly selective nitrating reagent, but its disadvantage is that it needs to use a large amount of acetic anhydride and the recovery of nitrating reagent is difficult, and it is still not economical

The disadvantage of this system is that anhydrous vanadyl nitrate is liquid at room temperature, and it is very easy to hydrolyze, and it will fail to be hydrolyzed in humid air, so it can only be dissolved in dichloromethane for storage and use, and it cannot be simply used after the reaction. Recycling will generate a large amount of waste to be further processed; there are other methods such as application of acid anhydride, peroxynitrite, nitrate-ionic liquid, nitrogen oxide / molecular sieve [X.Peng, H.Suzuki, Org. Lett.2001, 3, 3431] and other substances in the nitrification system have also been reported

[0009] Although these methods have their own advantages, they also have various disadvantages such as complex reaction system and cumbersome post-treatment.

Moreover, these nitration methods are generally liquid-phase reactions, which require a strong acidic environment and a large amount of organic solvents, and there are deficiencies such as difficult recovery of nitration reagents or the use of expensive phase transfer catalysts.