The cycloaddition reaction between diazonium salts and diazo compounds is a key step for synthesis of aryl pentazole.Herein,a series of diazonium salts with different acid anion including Cl-,HSO4-,and BF4-,are prepared and separated via the low temperature extraction method by using 4-aminophenol,2-methyl-4-aminophenol,and 2,6-dimethyl-4-aminophenol hydrochloride as raw materials.Their structure and morphology are characterized by means of spectroscopy,mass spectrometry,and scanning electron microscopy.Thermal stability study indicates that the stability of synthesized diazonium salt becomes poorer with the increasing number of methyl substitution adjacent hydroxyl group on benzene ring.It is worth mentioning that tetrafluoroborate diazonium has much better stability than sulfate diazonium salt and diazonium hydrochloride.Subsequently,aryl pentazole is synthesized by reaction between sodium azide and different diazonium salts,and the yield rates are determined by means of UV-Vis spectrum.Results indicate that the yield of synthesized aryl pentazole has inverse relation with the stability of diazonium salts,where 3,5-dimethyl-4-hydroxyphenyl diazonium hydrochloride with lower stability delivers a high yield of aryl pentazole.It is also observed that the yield of aryl pentazoles declines when the reaction temperature is higher than-30℃.
multi substituted aromatic aminesdiazonium saltthermal stabilityaryl pentazole
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