58results about "Nitro/nitroso group formation/introduction" patented technology

The invention relates to the nitration of aromatic or heteroaromatic compounds, wherein an activated aromatic or heteroaromatic compound and a nitrating agent, in the presence, if desired, of a solvent, are mixed intensely in a microreactor, and wherein the proportion of the nitrating agent to the activated aromatic or heteroaromatic compound, the concentration of nitrating agent in the reaction mixture, and the temperature are selected at levels such that the nitration begins autocatalytically, and wherein the nitration product is obtained after leaving the microreactor and, if desired, after an after-reaction time outside the microreactor.

A process for monitoring and/or controlling a nitrating process, having the following steps:

• • measuring inline infrared spectra of nitric acid content in a reaction mixture stream downstream of the nitration reaction, preferably near-infrared spectra,
  • evaluating the measured spectra by means of a computer-assisted, matrix-specific calibration model for the purpose of determining the content of nitric acid,
  • transmitting the results of spectrometric examination to a process control system,
  • inputting the results of spectrometric examination for the purpose of specifying the content of nitric acid in the acid phase into a regulator (224) for control of the metering (207,217) of nitric acid into a nitrating reactor.

A method of preparing carbamates of the general formula RR'-N-CO2-R'' by reacting an amine with carbon dioxide and an organic electrophile in an anhydrous solvent in the presence of a cesium base, whereby carbamate synthesis is accomplished in good yield at mild temperatures, either in solution or on a solid support, and wherein R, R', and R'' are hydrogen, alkyl of 1-18 carbon atoms, silyl, phenyl, benzyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, allyl, or heterocycle, which are widely used as industrial products, and as intermediates in organic synthesis.

The invention discloses a palladium-catalyzed ortho-orientation nitrification method of aza calixarene compounds, relating to a nitrification method, comprising the following steps: successively adding the aza calixarene compounds, palladium catalyst, nitrated reagent, oxidizing agent and reaction solvent in a sealed pressure container, controlling the pressure between 1 mbar and 100 bar, heatingthe mixture for 6-72 hour in an oil bath with the reaction temperature of 30-200 DEG C to obtain a product of the ortho-orientation nitrification. According to the invention, the method is carried out under neutral conditions, and has no generation of exhaust gas and waste water; directional mononitration is only carried out on the ortho-position of the nitrogen containing substituents without being influenced from other substituents on aromatic nucleus, and the chemo-selectivity and region-selectivity are good; the functional groups and the substrate have good adaptability, and the directional ortho-position nitration of a plurality of aromatic nucleus containing various substituents and a plurality of aromatic nucleus containing various nitrogen containing oriented groups can all be realized; and pre-functionalized aromatic compounds are not needed.

The invention relates to a production method of a chemical reaction process, and particularly relates to a production method of nitro compounds by tubular continuous nitrification reaction. The device comprises a tubular nitrification reactor, a tubular water-washing alkali-washing device, a nitrification mixture separator, and a water-washing alkali-washing separator. The nitrification raw materials and mixed acid flow, are mixed, react, and transfer heat in the tubular reactor; the separated nitro compounds are washed by water and alkali in a tubular manner to obtain qualified nitrification products; nitric acid is added from an inlet of the tubular nitrification reactor, or added respectively from the inlet and other parts of the tubular nitrification reactor. The production method for preparing nitro compounds by nitrification reaction provided by the invention realizes tubular continuous production, has high operation flexibility, high production efficiency, good product quality, few by-product, low energy consumption and raw material consumption, and safe and reliable production process. The invention is used for heat extraction nitrification and heat insulation nitrification.

A method of nitrating a compound selected from the group consisting of

is provided.

The invention relates to a nitration method having the following principles: a phosgene species is converted with two equivalent silver nitrates into a double-mixed anhydride of carbonic acid and nitric acid, known here as carbonic acid dinitrate (I). Said operation is carried out in situ, and the formed dinitrate decomposes spontaneously. In addition to carbon dioxide, nitrate ions and nitronium ions are formed, said ions comprising electrophiles which are necessary for nitration. The solution which is used is acetonitrile, and is insignificant if the alcohol species is dissolved or suspended. The necessary equivalent silver nitrates are introduced into the system and optionally heated or cooled to the desired temperature. Subsequently, the acid chloride is introduced slowly, drop by drop or slowly little by little. Phosgene, diphosgene, triphosgene and chloroformic acid ester can be used as carbonic acid dichloride and monochloride, and their thiocarbonic acid analogues. A brown colouration and precipitated silver chloride display the formation of the carbonic acid reactants, said brown colouration rapidly discolouring due to an immediate reaction of the nitronium ions with the substrate with is to be nitrated. Towards the end of the addition of phosgene, the brown colouration remains for longer and longer until it no longer disappears. Then, it is stirred for another hour at room temperature. In the event of high acid-sensitive educts, non-nucleophilic nitrogen bases such as DBU can be added to the system in order to intercept the formation of nitric acid.

The invention provides a method for synthesizing a beta-iodo-nitroolefin compound as shown in a formula (III). The method comprises: mixing substituted alkyne shown in a formula (I), an iodine source and tert-butyl nitrite shown in a formula (II) in a solvent for completely reacting to obtain reaction liquid, and after reacting for 4 to 6h at a temperature of 25 to 80 DEG C, processing the reaction liquid to obtain the beta-iodo-nitroolefin compound, wherein the solvent is tetrahydrofuran, acetonitrile, acetone or 1,2-dichloroethane, and a ratio of quantities of fed substances, i.e., the substituted alkyne shown in the formula (I), the iodine source and the tert-butyl nitrite shown in the formula (II), is 1 to (0.5 to 1) to (2 to 5). The method provided by the invention is high in substrate adaptability and mild in reaction condition, does not relate to use of an oxidizing agent and a metal catalyst, is safe and environmental-friendly, is simple in reaction operation, and is more beneficial to application in medicine synthesis. The formulas are shown in the description.

The invention describes the synthesis of novel mono-amine and di-amine derivatives of hexa-nitro-hexaazaisohexawurtzitane (CL-20). The synthesis is effected by the novel use of fluoroacylating compounds to protect the secondary amine groups of acylated precursors to CL-20 against nitrolysis. In so doing the mono-amine and di-amine derivatives of CL-20 are rendered and which in turn may be subsequently utilised as intermediates to generate further novel derivatives with differing physical and chemical properties to the parent compound. Formula (I), wherein:- X=H, and Y=H or NO2.

Aromatic amines are produced from aromatic hydrocarbons by

• • a) reacting the aromatic hydrocarbon(s) with a mixture of nitric acid and sulfuric acid to generate a two-phase reaction mixture,
  • b) separating the reaction mixture into an aqueous acid phase and an organic phase containing the nitroaromatic compounds
  • c) washing the organic phase to purify the nitroaromatic compound(s),
  • d) hydrogenating the nitroaromatic compound(s) in the presence of a catalyst to produce the aromatic amine(s) and water of reaction, and
  • e) separating the water of reaction formed in step d) from the aromatic amine(s),

in which the water of reaction separated in step e) is used to wash the organic phase containing the nitroaromatic compounds in step c).

The invention discloses an environment-friendly bionic catalytic nitration method for a phenolic compound and belongs to the technical field of organic synthesis. The method provided by the invention comprises the steps of dissolving the phenolic compound, which serves as a raw material, in a solvent at normal temperature, adding sodium nitrite into the solution, then, dropwise adding hydrogen peroxide into the reaction solution, adding metal-doped Al-MCM-41 molecular sieves into the reaction solution at normal temperature so as to start a reaction, carrying out stirring so as to carry out a nitration reaction, and then, carrying out suction filtration, organic solvent extraction, depressurized concentration and column chromatography separation, thereby obtaining a target product. According to the nitration method disclosed by the invention, the reaction conditions are mild, heating is not required, the operation is convenient, and the product is easy to treat. The nitration method is applicable to an environment-friendly bionic catalytic nitration reaction for phenolic compounds.

The invention discloses a synthesizing method of an alpha, beta unsaturated nitroolefin derivative. The synthesizing method includes: allowing an alkene compound to have one-pot reaction in a tert-butyl hydroperoxide system containing tetra-arylated ferroporphyrin (III) and halogenated ammonium salt to generate the alpha, beta unsaturated nitroolefin derivative. By the method, the alpha, beta unsaturated nitroolefin derivative with high E three-dimensional selectivity is synthesized under mild reaction conditions in a high-yield manner.

The invention discloses a synthesis method of substituted nitroaniline, comprises the following steps: performing nitration on the substituted aniline and nitrite in a solvent at 20-80 DEG C to obtain the substituted nitroaniline, the structural formula of the substituted aniline is as shown in the specification, wherein R1 is p-Toluenesulfonyl, acetyl, t-butyloxycarbonyl, benzoyl, -COC(CH3)3, benzyl or methyl; R2, R3, R4, R5 and R6 are respectively and independently C1-C4 alkyl, C1-C4 alkoxy, halogen, H, NO2, OCF3 or aryloxy, at least one of R2, R4 and R6 is H, the nitration means that at least one of R2, R4 and/or R6 with value of H on the substituted aniline is substituted by NO2. The synthesis method disclosed by the invention is free from high-temperature and high-pressure, the condition is gentle, the operation is safer, the strong acid is avoided, the post-treatment is simple, and the pollution to the environment is small, and the harm is light.

A method for the nitration of aromatic hydrocarbons (I) by liquid-phase reaction with a nitrogen oxide (NO, N2O3, NO2 or N2O4) and an oxygen-containing gas stream in presence of a heterogeneous oxide catalyst, in which the reaction is started in presence of at least 0.1 mol% water (based on I).

The invention relates to a nitration method of an aromatic hydrocarbon compound, in particular to a method for preparation of a nitro aromatic hydrocarbon compound by subjecting an aromatic hydrocarbon compound to nitration reaction with liquid dinitrogen tetroxide and oxygen-containing air flow in the presence of a solid acid catalyst and a small amount of sulfuric acid. And the method is a production process suitable for industrialization.

The invention provides an organic-matter nitrosoation method with no production of nitric oxide waste gas, which belongs to the technical field of clean chemical processes and comprises nitrosoation reaction. The method is characterized in that the nitrosoation reaction is performed in closed space, and the highest pressure in the closed space is 0.4 to 0.6 MPa. The method prevents nitrous acid from being decomposed by sealing and pressurizing equipment so as to avoid producing nitric oxide waste gas. The method has the advantages of ensuring no emission of nitric oxide gas during production, producing no environmental pollution, saving raw material and reducing production cost.

The invention provides a nitration reaction stabilizer and application thereof. The stabilizer comprises isooctyl dimethyl dithioglycolate tin, butyl epoxy stearate, barium stearate and trioctyl phenyl phosphite. The stabilizer can prevent explosive products from generation in the nitration reaction so as to avoid the resulting dangerous accidents, and is a stable composition with excellent stability.

A process to isolate a compound of Formula (2a) or a salt or solvate thereof, comprising a) reacting a mixture of diastereoisomers of Formulae (2a, 2b) with a basic heterocyclic-aldehyde compound and an optically active amine in the presence of a base; and b) separating the compound of Formula (2a) from the product of step a) by acid extraction. The compound of Formula (2a) may be produced with an enantiomeric excess of 98%. Compounds of Formula (2a) are useful intermediates in a process to prepare a bicyclic γ-amino tetrazole derivative of Formula (I) which finds utility in treating neuropathic pain and disorders of the central nervous system.

The present invention discloses an improved process for the liquid phase nitration of aromatic compounds catalyzed by WO3 supported on mesoporous silica support, at low temperature, with high conversion and selectivity.