48 results about "Nitrochlor" patented technology

The invention relates to a preparation method of paranitroaniline. The preparation method comprises the following steps that: (1) a high-pressure conveying pump is used for respectively pumping p-nitrochlorobenzene and stronger ammonia water with the concentration being 45 to 55 weight percent into a tubular mixer according to a weight ratio of 1:(3.0-4.0), and a mixed material is obtained through sufficient mixing; (2) the mixed material is continuously conveyed into a pipeline reactor for reaction, the reaction temperature is 235 DEG C to 245 DEG C, the pressure is 10.0 to 14.0MPa, the reaction time is 40 to 90 minutes, after the reaction is completed, the materials are discharged into a low-pressure reaction kettle by a pressure relief valve, and ammonia is recovered through ammonia release; and (3) after the ammonia recovery, the separation is carried out, the materials are centrifuged and washed after the separation completion, and the paranitroaniline is obtained after the materials are centrifuged to the dry state. The method provided by the invention belongs to a method for continuously producing the paranitroaniline, the production is safer, the production capability is higher, the appearance and the purity of the obtained products are respectively improved, the product quality is excellent, and in addition, the cost is reduced.

The invention discloses a method for preparing intermediate 5-bromo-2-methylpyridine. In the prior art, the dosage of aluminium trichloride is large; the catalytic effect is poor; the by-products are more; the yield of products is low; and the obtained products are difficult to separate. The method comprises the following steps: reacting diethyl malonate with alkali metal to generate salts, dripping 5-nitryl-2-chloropyridine into the salts for condensation reaction, and subsequently performing decarboxylation on the obtained product under acidic condition to obtain 5-nitryl-2-methylpyridine; performing hydrogenation reduction on the 5-nitryl-2-methylpyridine under the catalysis of Pd/C catalyst to obtain 5-amido-2-methylpyridine; and reacting the 5-amido-2-methylpyridine with acid to generate salts, dripping bromine, dripping a sodium nitrite water solution, and obtaining the 5-bromo-2-methylpyridine. The method has mild reaction conditions, easy operation, simple post-treatment, good catalytic effect, high yield of each step and high yield of final products, and is particularly suitable for industrialized production.

A special feeding mode is adopted in the invention to reduce generation of nitrophenol, and is characterized in that a sodium methoxide solution prepared from methanol and sodium hydroxide is added to an autoclave in t he production process of nitroanisole from m-oil (o-nitrochlorobenzene, p-nitrochlorobenzene and m-nitrochlorobenzene) in the autoclave, so generation of nitrophenol is reduced, thereby the reaction time is greatly shortened, the raw material conversion rate is improved, the reaction selectivity and the yield of the above product are improved, the cost is reduced, and three wastes are reduced.

The invention discloses a method for preparing 3,3'-dichlorobenzidine hydrochloride through the rearrangement reaction of hydrogen chloride. By using an existing technique, ortho-nitrochlorobenzene is added into an organic solvent and alkaline liquor under the catalysis of a precious metal catalyst and a cocatalyst, and then the obtained object carries out a coupled reduction reaction with hydrogen, so that 2,2'-dichlorohydrazobenzene is obtained; and hydrogen chloride gas is fed into a 2,2'-dichlorohydrazobenzene solution dissolved by using an organic solvent to carry out a rearrangement reaction, so that 3,3'-dichlorobenzidine hydrochloride is obtained. The yield can reach over 95%, the reaction process can be intermittent, semi-continuous and continuous reaction processes, and the method is low in viscosity of reaction process, easy to uniformly stir and low in energy consumption, and has a yield higher than that in a traditional process, therefore, the method has a good industrialization prospect.

The invention provides ano-chloroaniline preparation method, wherein the raw materials comprise: o-nitrochlorobenzene, a catalyst, dicyandiamide, a solvent, nitrogen and hydrogen. According to the invention, Ru/C is used as the catalyst, and has characteristics of simple components, stable activity and high selectivity, and dicyandiamide is used as the dechlorination inhibitor, so that the dechlorination side reaction is effectively inhibited, the conversion rate is high, and the selectivity is high; by improving the structure of the rectifying tower, the vapor-liquid mass transfer performancein heat transfer and mass transfer is improved, and the contact area between the gas phase and the liquid phases is increased by utilizing the auxiliary member; the turbulent flow degree is effectively increased through the inflow weir having the step structure and the turbulent flowblock, so that the mass transfer and heat exchange efficiency and the mass transfer and heat exchangerate between the gas phase and the liquid phases are improved; and the treatment and circulation capacities of the liquid phase are improved through the circulation tank, and the gas-liquid phase contact time is favorably prolonged by using the baffle arrangement of the downcomer and the inner diameter change, so that the yield and the purity of o-chloroaniline are improved.

The invention provides diphenyl disulfide type vulcanized peptizer intermediate, namely 2,2'-dinitro-diphenyl disulfide and a preparation method thereof. The preparation method is characterized in that ortho-nitrochlorobenzene, industrial sodium sulfide and sulfur powder are adopted as raw materials, and the 2,2'-dinitro-diphenyl disulfide is synthesized in ethanol. The preparation method has the advantages of simple reaction process and high purity of obtained products.

The invention belongs to the technical field of high-molecular compounds. The invention provides a dual-response dipeptide supramolecular polymer, which is a dual-sensitive supramolecular polymer prepared by the following steps of: modifying a hypoxic response element p-nitrochloroformic acid benzyl ester or 2-(2-nitroimidazole-1-yl) acetic acid at an N terminal and modifying a temperature-sensitive element dendritic alkoxy ether at a C terminal through tryptophan glycine dipeptide by adopting a liquid phase synthesis method, and performing self-assembly in an aqueous solution. The supramolecular polymer is simple to prepare; the fluorescence intensity is greatly enhanced under the hypoxic condition through the fluorescence characteristic of tryptophan; meanwhile, the polymer can coat the medicine; the polymer is disassembled under the hypoxic condition to realize the release of the medicine; and a research basis is provided for the research and development of a novel nano-medicine carrier.

Disclosed herein a process preparation of 2,6-dichlorobenzonitrile. A process of making high yield, high purity 2,6-dichlorobenzonitrile including the selective de-nitrochlorination of 2-chloro-6-nitrohenzonitrile by treatment of the 2-chloro-6-nitrobenzonitrile with chlorine gas.

The invention provides a preparation method of ortho-aminophenol, which specifically comprises the following steps: (1) taking water, nitrobenzene and sulfuric acid as raw materials, adding a catalyst, and preparing an initial reaction solution under the condition of introducing hydrogen; (2) carrying out solid-liquid separation on the initial reaction solution, taking a solid substance as the catalyst, and reusing the solid substance in S1, wherein a liquid substance is a mixture solution; and (3) adjusting the pH of the mixture solution by a basic substance to neutrality. According to the preparation method of ortho-aminophenol, nitrobenzene is used for replacing ortho-nitrochlorobenzene, high-pressure hydrolysis and high-temperature and high-pressure reduction are not needed, reaction conditions are mild, the operation process is simple, safety is high, production efficiency is high, productivity is high, the product cost is reduced, and the overall benefit is increased.

The invention provides a novel method for synthesizing 3, 5-dinitrobenzyl chloride. The novel method comprises the following steps: a, carrying out reduction reaction on 3, 5-dinitrobenzoyl chloride and a reducing agent in a first solvent to obtain 3, 5-dinitrobenzene methanol; and b, carrying out chlorination reaction on the 3, 5-dinitrobenzene methanol, a chlorination reagent and a catalyst in asecond solvent to obtain the 3, 5-dinitrobenzyl chloride. According to the method, the reduction process of the 3, 5-dinitrobenzoyl chloride is remarkably improved, a simple reducing agent is used, nitro reduction is avoided under the assistance of Lewis acid and Lewis alkali, and the reaction selectivity and the product yield are improved.

The invention provides a method for preparing a DCB reduzate through continuous catalytic hydrogenation reduction. The method comprises the following steps: adding o-nitrochlorobenzene, toluene, caustic soda liquid with a concentration of 30%, desalted water and a Pt/C catalyst into three continuous tank reactors connected in series, and ending a first-stage intermittent reaction until all reactions do not absorb hydrogen; opening overflow discharge valves of the three tank reactors, and simultaneously pumping o-nitrochlorobenzene, methylbenzene, caustic soda liquid with the concentration of 30% and desalted water into the first tank reactor in proportion by using a metering pump; and continuously introducing hydrogen for catalytic hydrogenation to prepare the DCB reduzat, namely, 2,2-dichlorohydrazobenzene. According to the invention, the loss of the catalyst due to frequent filtering in a batch reaction process can be effectively reduced, internal recycling of the catalyst is achieved, and the service life of the catalyst is prolonged; meanwhile, the tank reactors are relatively small in size, reaction stability is good, product dechlorination is relatively low, selectivity is high and relatively few byproducts is produced; and in addition, exhaust emission in the continuous reaction is greatly reduced, so the environmental pollution is greatly reduced.

The invention discloses a synthesis method of 3-methyl-4-nitrodibenzofuran, and belongs to the technical field of organic synthesis. The synthesis method comprises the following steps: S1, reacting o-chlorophenol with an alkali I to form a salt, then performing a nucleophilic substitution reaction on the salt and 2-nitro-3-chlorotoluene to obtain a mixture I, and performing post-treatment on the mixture I to obtain an intermediate 1; and S2, dissolving the intermediate 1 and 1,3-bis(2,6-diisopropylphenyl)imidazolium chloride in an aprotic polar solvent, performing an intramolecular cyclizationreaction under the action of a Pd catalyst and an alkali II to obtain a mixture II, and performing post-treatment on the mixture II to obtain 3-methyl-4-nitrodibenzofuran. The synthesis method has the advantages of simplicity, cheap raw materials, easiness in purification, and avoiding of the problems of expensive raw materials and low yield in the traditional method.

The invention relates to the technical field of organic intermediates, and particularly discloses a p-nitroanisole synthesis method. The method includes the steps: S1 dissolving p-nitroanisole, and dissolving sodium hydroxide and methanol in an organic solvent to form a first mixed solution, wherein the molar ratio of sodium hydroxide to methanol is (1.3-2): 8; S2, performing preliminary reaction,wherein p-nitrochlorobenzene is added into the first mixed solution for 2-3 h, and a second mixed solution is formed, and the molar ratio of the p-nitrochlorobenzene to the addition amount of the methanol in S1 is 1: 8; S3, carrying out secondary reaction: a catalyst is added into the second mixed solution, a quaternary ammonium salt catalyst is selected as the catalyst for 4-8 h, and the molar ratio of the addition amount of the catalyst to the addition amount of the methanol in S1 is (0.003-0.006): 8; S4, carrying out post-treatment, and carrying out post-treatment to obtain p-nitroanisole.By adding the quaternary ammonium salt catalyst, the final yield of p-nitroanisole can be improved.