o-Nitrotoluene can be used as a raw material to synthesize other compounds such as o-nitrobenzaldehyde, o-nitrobenzoic acid, and dinitrotoluene.
1. For the preparation of o-nitrobenzaldehyde. Take o-nitrotoluene as raw material, select the metal phthalocyanine of general formula (I) structure, the mononuclear metalloporphyrin of general formula (II), (III) structure or the μ-oxygen binuclear metalloporphyrin of general formula (IV) structure Any one of the phenoline is used as a catalyst, in the formula, M1, M2, M3, M4, M5 are transition metal atoms, M1=Fe, Co, Cu, Zn, M2=Fe, Mn, Co, Cu, Zn, M3= Fe, Mn, Co, M4 and M5 can be the same or different, when they are the same, M4=M5=Fe, Mn, Co, when not, M4=Fe, M5=Mn or M4=Fe, M5=Co, R can be It can be carboxyl or hydrogen, R1 and R2 can be hydrogen, halogen, nitro, hydroxyl, alkoxy, ligand X is chlorine, the amount of catalyst used is 0.2-1.0% of the weight of o-nitrotoluene, and methanol is used as Solvent, in 3.0～6.0mol/L strong alkaline methanol solution, pass oxygen of 0.8～3.0MPa, control the reaction temperature to be 25～60℃, and the reaction time to be 6～48h to obtain the crude product of o-nitrobenzaldehyde. After separation as well as purification by conventional methods, o-nitrobenzaldehyde penalty items are obtained.The structures of general formula (I), (II), (III) and (IV) are respectively as follows:
2. For the preparation of o-nitrobenzoic acid. Without adding any catalyst, using o-nitrotoluene as raw material, oxygen as oxidant, sodium hydroxide as alkali, the reaction temperature is 25-85 ℃, and the reaction is carried out in solvent alcohol or its aqueous solution for 5-72 hours. Treatment, separation and purification to obtain the o-nitrobenzoic acid.Therapy, splitting up and purification to acquire the o-nitrobenzoic acid. The method calls for no stimulant; the raw materials and solvents are cheap; the reaction temperature is moderate; the manufacturing control is easy, the return can be as high as 90%,. and it is suitable for mass preparation and industrialization, and has broad application prospects.
3. For the preparation of dinitrotoluene. Using o-nitrotoluene as raw material, using fuming acid sulfur-fuming nitric acid nitration system to carry out nitration reaction at room temperature, the dinitrotoluene mixture was obtained in high yield. The proportion of 2,4-DNT in the dinitrotoluene mixture can reach 75%. By taking on the nitration reaction at space temperature level, the generation of trinitrotoluene is avoided, and also the safety and security of the nitration process is enhanced.Specifically, it includes the following steps: in the first step, add fuming sulfuric acid to the reactor first, then dropwise add o-nitrotoluene, and then add fuming nitric acid after mixing evenly, and continue the reaction; in the second step, after the reaction is completed, add the mixed solution Pour into crushed ice to precipitate solids. After the ice cubes are completely melted, the solids obtained by suction filtration are washed with hot water, cooled, suction filtered, and dried to obtain dinitrotoluene. Wherein, the mass fraction of sulfur trioxide in the oleum in the first step is 5~25%; the consumption ratio of o-nitrotoluene, oleum, concentrated nitric acid is 1 mol: 0.40~0.65 L: 1~1.05 mol In the first step, the temperature of reaction is maintained at 5～30 ℃, and the reaction times is 2～3h; In the second step, the mass fraction of 2,4-dinitrotoluene in the obtained dinitrotoluene is 72～75% ; The nitrification process adopts discontinuous production or continuous production.