Study For The Synthesis Of O-Amino-P-Methylphenol

O-amino-p-methylphenol which will be introduced in this article is a veryimportant intermediate of dye. It can be used to synthesize dye and polyester fiberfluorescer DT et. al. But many shortcomings, such as low automated level,high cost andsevere contamination,have been appeared in the processes of producing this compoundin our nation.Three different catalytic reductive methods forming o-amino-p-methylphenol byo-nitro-p-methylphenol were compared in order to overcome above shortcomings.Raney-Ni(self-commond) is the catalyst in the liquid phase hydrogenation ofo-nitro-p-methanephenol in the first method; Iron oxide hydroxides(self-commond) isthe catalyst in the presence of 80％hydrated hydrazine in second method to reduceo-nitro-p-methylphenol.The last one,α-Amylase which has been immobilized to reduceraw material.All kinds of conditions and their effects in the three reactions were discussed.Finally the optimal experimental conditions were obtained according to these effects.The optimal conditions in the first process are: the reaction temperature is90-100℃;the pressure exent of handling process is 84±1 kgf/cm~2;the dosage of catalystis 5％of the raw material;the stirring revolution is 500r/min.In this process,the yield ofo-amino-p-methanephenol was over 94％, the catalyst of Raney-Ni could be reused forseven times but still remained high activity under these optimum conditions.Additionally the catalyst can be used after reactivation for another five times. Theoptimal conditions in the second process are:the reaction temperature is 78℃; reaction last 8 hours and the dosage of catalyst is 0.8g. The transformation efficiency of theo-nitro-p-methanephenol was over 98％, the yield of o-amino-p-methanephenol wasover 95％under these optimum conditions. The optimal conditions in the last oneare: the immobilizedα-Amylase was actived with amidon in the solution of pH=7 for4min at 70℃; The reaction conditions in the synthetic process: temperature is 100℃;the mixing solution which was composed of methanol:water=1:10, reaction lasted 12hours,the yield of production was over 49％.Otherwise, immobilizedα-Amylase wasemployed for four times.