Method for synthesizing mononitrotoluene by modified attapulgite catalyst

The present invention discloses a process for catalytic synthesis Pronting mononitrotoluene, the synthesis method comprises the following steps: First, the mass concentration of 65% -98% concentrated nitric acid attapulgite soaking 12h-48h, filtered dried at room temperature to give Pronting catalyst; secondly, toluene was added and Pronting catalyst in a container, mechanical stirring at room temperature, 1-2 drops / sec was added dropwise a concentration of 90% -95% by mass of concentrated nitric acid, by circulating water cooling to control the reaction temperature was 50oC-55oC, 1h-2h the reaction was complete; Finally, the reaction product caustic sequentially, separated, washed with water to give a yellow nitrotoluene recycling after the catalyst was dried Pronting. Low price Pronting catalyst of the present invention, a simple manufacturing process, low production cost and high yield mononitrotoluene, a simplified production process nitrotoluene, and concentrated sulfuric acid without recycling.