Research On Synthesis Of Aromatic Nitriles From Aromatic Olefins With Sodium Nitrite As The Nitrogen Source And Oxidant

Nitriles are widely used in synthetic organic chemistry, chemical industry as well as biological applications, as they serve as important building blocks in the pharmaceutical, fine chemical, dye, and agrochemical industries.Traditionally, these nitriles are synthesized by metal cyanides-catalyzed cyanation of alkyl and aryl halides, Sandmeyer reaction of aromatic hydrocarbons on a bulk scale. Apart from C-X bond, C-O, C-N,C-C, C-H, C=O, ON, and C=C bonds were also found to be converted successfully to C=N bond with relatively low toxic nitrogen sources.Olefins are important petrochemical and products in coal chemical industry, even are easily accessible from renewable resources, such as seed oil. The widely available olefins, which could convert to various organic chemicals, are significant ingredient in organic synthesis. Therefore, the preparing of nitriles from transforming C=C bond of cheap and readily available hydrocarbons to C=N bond has potential industrial value. Although the preparation method nitriles from olefins are not mature with a handful of precedents, this converting of C=C bond to C=N bond is worthy to research.Herein, we report a synthesis of aromatic nitriles from aromatic olefin with nitrite as the nitrogen source and oxidant under mild condition. The main contents of this article include:1. The synthesis of benzonitrile from styrene with nitrite as the sodium nitrogen source and oxidant was studied. The influence factors of the reaction, such as, the dosage of NaNO2 and acid, the variety of acid and solvent, temperature and time were investigated. From these laboratory results, the optimized conditions were determined; Based on the optimized conditions of synthesis of benzonitrile from styrene, the temperature and time of preparing benzonitrile from cinnamyl chloride were studied, and the the optimized conditions were determined.2. The reaction with the terminal or internal olefins as substrate were explored under the optimized conditions, and product of aromatic nitriles were isolated by.column chromatography and detemined by GC-MS and 1H NMR and 13C NMR spectras. The results indicated that the number, property and substituted situation of groups connecting with olefins have significant influence onthe synthesis nitriles and it was more difficult forinternal olefins converting to nitriles comparing to terminal olefins.3. The reaction mechanism of synthesis of benzonitrile from cleavage of C=C double bond with nitrite as the nitrogen source and oxidant was investigated. The results showed the a-nitro-ketoxime was the important intermadiate of this nitrogenation reaction.