7 results about "O-nitrotoluene" patented technology

The invention belongs to the technical field of organic synthesis, and relates to a preparation process of o-nitrobenzaldehyde. According to the method, o-nitrotoluene is taken as a starting raw material, hydrogen peroxide is taken as an oxidizing agent, water is taken as a solvent, under the protection of nitrogen, under the action of a phase transfer catalyst tetrabutylammonium bromide and a catalyst manganese dioxide, o-nitrotoluene is subjected to oxidation reaction to obtain o-nitrobenzaldehyde, water is taken as a solvent, bromine and wastewater containing bromine, chromium and the like are not used, the operation is simple and convenient, and the method is suitable for industrial production. The process temperature is mild and easy to control, and the obtained product is stable in quality, low in impurity content and remarkable in environmental benefit.

The invention belongs to the field of organic synthesis, and relates to a synthesis method of o-nitrobenzaldehyde, in particular to a heteropolyacid catalyzed safe and green synthesis method of o-nitrobenzaldehyde. The method comprises the following steps: stirring and heating o-nitrotoluene serving as a raw material in an organic solvent under the action of heteropoly acid (HPA), and cooling and directly filtering after the reaction is finished to obtain the o-nitrobenzaldehyde. And the heteropoly acid is Na2H8 [MnV13O38], Na2H8 [MnV15O38] or Na2H8 [MnV17O38]. The invention further discloses a preparation method of the heteropoly acid. The method has the advantages of low material cost, mild reaction conditions, less three wastes in the production process, short process flow and effective reduction of the production cost. And the prepared o-nitrobenzaldehyde is relatively high in yield and purity.

The application discloses a device and method for treating nitro compounds in a gas phase channel of a vacuum concentration device for waste sulfuric acid of polynitrotoluene, wherein the device is supplemented with o-nitrotoluene in the three-stage and four-stage condensers to reduce the freezing point of the acid vapor feed; and the heavy phase containing o-nitrotoluene separated by the three-stage and four-stage condensers is supplemented to the two-stage condenser to reduce the freezing point of the acid vapor feed of the two-stage condenser, thereby solving the problem of nitro compound accumulation in the existing treatment system.

The invention relates to the technical field of pesticide intermediate production, and discloses a pesticide intermediate continuous chlorination reaction method and equipment, and the method comprises the following steps: dehydrating an o-nitrotoluene raw material, preheating to 60-70 DEG C, filtering a ferric trichloride / diluted hydrochloric acid solution with the concentration of 10-15 wt%, continuously injecting into a reaction system, and reacting for 2-4 hours; the o-nitrotoluene pretreated in the step a, the ferric trichloride solution obtained in the step b and dry chlorine are introduced into the reaction equipment according to the flow velocity of 8-10 L / h, 1.0-1.5 L / h and 0.8-1.0 m < 3 > / h, the reaction temperature is controlled to be 60-70 DEG C, the system pressure is 0.4-0.6 MPa, and the retention time is 30-40 minutes. The device has the following advantages and effects: full-automatic regulation and control from raw material dehydration to tail gas emission are realized, the requirements of automatic chlorination production are met, gas-liquid two-phase segmented mixing is realized in a manner of efficient mass and heat transfer and multiple interfaces, the reaction efficiency is improved, dichloro side reaction is inhibited in a manner of multi-segment temperature control, and the selectivity of monochlorinated products is improved.

The application discloses o-nitrobenzaldehyde and a synthesis method thereof, and belongs to the technical field of medical intermediates. The synthesis method comprises the following steps: dissolving o-nitrotoluene, dibromohydantoin and azobisisobutyronitrile in mixed organic solvents to perform a bromination reaction, then performing filtration, impurity removal, extraction and organic phase drying in sequence, and separating o-nitrodibromobenzene; adding the o-nitrodibromobenzene into a DMSO solution, adding calcium carbonate to perform an oxidation reaction, then performing filtration, extraction, organic phase drying and purification and decoloration in sequence, and obtaining o-nitrobenzaldehyde. The o-nitrobenzaldehyde is obtained through a bromination oxidation two-step reaction, the synthesis method has the advantages of simple process, low cost, small pollution and high product yield.

The application relates to the technical field of organic synthesis, and particularly discloses a high-efficiency synthesis method of indole-2-carboxylic acid, which comprises the following steps: preparing a high-activity catalyst; preparing a solution containing ethyl nitrophenyl pyruvate by taking o-nitrotoluene and diethyl oxalate as starting materials; adding the solution containing ethyl nitrophenyl pyruvate into a high-pressure kettle, adding the high-activity catalyst, replacing air in the high-pressure kettle with nitrogen, then performing a catalytic hydrogenation reaction, cooling to room temperature after the reaction is completed, filtering the reaction liquid after pressure relief, removing the solvent from the filtrate, and recrystallizing the solid with ethanol to obtain indole-2-carboxylic acid. The application takes o-nitrotoluene and diethyl oxalate as starting materials, synthesizes the target product through two-step reactions, the above conditions are mild and low in cost, the catalyst used in the reaction process is high in catalytic activity, good in cycle stability and easy to recycle.

The invention provides a method for preparing a key intermediate of a dibenzazepine drug. Specifically, the invention provides a preparation method of a compound as shown in a formula IV, which comprises the following steps: carrying out condensation reaction on o-nitrotoluene and o-chlorobenzaldehyde to obtain a compound as shown in a formula I, then carrying out hydrogenation reduction to obtain a compound as shown in a formula II, and then carrying out intramolecular coupling reaction to obtain a compound as shown in a formula III, and finally, dehydrating to obtain the compound as shown in the formula IV. Compared with a reaction route with harsh reaction conditions and high requirements on reaction equipment in the prior art, the method disclosed by the invention has the advantages of simple reaction route, mild reaction conditions, easiness in industrial production and high product yield. # imgabs0 #