27 results about "Bromide methyl" patented technology

The invention belongs to the technical field of organic synthesis, and particularly relates to a synthesis method of an isoxazole compound under a visible light catalysis condition. The method comprises the following steps: dissolving a compound 1 in 1, 2-dichloroethane, then adding tert-butyl nitrite, tribromomethane, alkali and a photocatalyst, in an inert gas environment, irradiating with visible light and stirring at room temperature to react, after the reaction is completed, reducing pressure to remove a solvent, and then performing silica gel column purification on a crude product to obtain a product, namely the isoxazole compound. The brand-new method for preparing the isoxazole compound through visible light catalysis is developed, the conditions of high temperature and high pressure in a traditional synthesis method are avoided, energy consumption and environmental pollution are remarkably reduced, and the yield of the isoxazole compound is effectively increased by regulating and controlling reaction conditions and optimizing raw material selection and proportion.

The invention discloses a method for synthesizing a chlorfenapyr bisamide intermediate by a one-pot method, which comprises the following steps: by taking aniline as an initial raw material, reacting the aniline with 2-bromoheptafluoropropane under the action of a catalyst and an acid-binding agent to generate 4-heptafluoroisopropylaniline, distilling to recover excessive 2-bromoheptafluoropropane after the aniline is completely converted, and separating the 2-bromoheptafluoropropane from the 4-heptafluoroisopropylaniline to obtain the chlorfenapyr bisamide intermediate. Adding bromotrifluoromethane into the reaction liquid to react to obtain 2-trifluoromethyl-4-(heptafluoroisopropyl) aniline, then carrying out oxidation-reduction reaction on the dropped hydrogen peroxide and excessive sodium hydrosulfite, and after the sodium hydrosulfite is completely consumed, reacting to obtain 2-trifluoromethyl-4-(heptafluoroisopropyl) aniline; and carrying out benzene ring bromination reaction on dropwise added hydrogen peroxide, the brominating agent in the reaction liquid and the 2-trifluoromethyl-4-(heptafluoroisopropyl) aniline to obtain the 2-bromo-4-(heptafluoroisopropyl)-6-(trifluoromethyl) aniline, wherein the brominating agent in the reaction liquid and the 2-trifluoromethyl-4-(heptafluoroisopropyl)-6-(trifluoromethyl) aniline are subjected to benzene ring bromination reaction. The method is simple in process, high in yield, low in raw material cost and suitable for industrial production.

The present application relates to a kind of preparation method of trifluoromethyl pyrazole compound, belong to the technical field of organic synthesis.The specific method is: (1) trifluoroacetyl ethyl acetate is first with hydrazine hydrate cyclization reaction and generates compound of formula III;(2) under the catalysis of base, compound of formula III is reacted with difluoromethylation reagent and generates compound of formula II;(3) compound of formula II is reacted with methylating agent and obtains compound of formula I;The difluoromethylation reagent is difluoro-monochloromethane or sodium difluoro-monochloroacetate;The methylating agent is chloromethane, bromomethane, iodomethane, dimethyl sulfate or dimethyl carbonate.The present application is prepared by changing reaction route, and the higher-priced raw material methylhydrazine is replaced, and isomer impurity is no longer generated in the product prepared.Not only raw material cost is reduced, but also the purity of product is improved.

The application discloses a kind of ultrafast metal-free and solvent-free preparation method for preparing symmetric and asymmetric disulfide, which comprises the following steps: at room temperature, raw material R-SH, R'-SH and oxidant and base are added to reaction bottle, shake rapidly for 10-30 seconds, and R-S-S-R' is prepared after the reaction product is purified;Wherein R in R-SH is aliphatic or aromatic group, R' in R'-SH is aliphatic or aromatic group;R in R-SH and R' in R'-SH are same or different;The aromatic group has substituent or no substituent, and the aliphatic is straight chain or has branch;The oxidant is chloroform, and the base is N, N-diisopropylethylamine (DIPEA).The method is simple in operation, high in yield (60-99%), ultrafast in reaction kinetics, greatly improves production efficiency, wide in applicability, avoids the use of organic reaction solvent, raw material is cheap and easy to obtain, and does not contain residual metal and other sticky contaminants from reagent and ligand, provides a safer and more effective method for the synthesis and production of symmetric and asymmetric disulfide-containing compounds.

The invention relates to a preparation method of methylenecyclopentane and a composition containing the methylenecyclopentane, in particular to a method for synthesizing the methylenecyclopentane by reacting substituted triphenylphosphine (such as tris (4-methoxyphenyl) phosphine and the like) with methyl iodide / methyl bromide to generate substituted methyl triphenyl phosphonium halide and then reacting with cyclopentanone through Wittig in the presence of alkali. Compared with the traditional method, the method has the advantages that the byproduct is substituted benzene (the boiling point is more than 100 DEG C), the boiling point of the substituted benzene is obviously different from that of the target product (the boiling point is 77 DEG C), methylene cyclopentane with the purity of more than 99% can be obtained through simple rectification, and the yield reaches 85-95%.

The present invention relates to the technical field of fruit fumigation, and in particular to a fumigation device for automatically fumigating fruits with methyl bromide gas. The present invention provides a fumigation device for automatically fumigating fruits with methyl bromide gas that can detect the concentration in real time and accelerate the circulation. A fumigation device for automatically fumigating fruits with methyl bromide gas includes a fumigation box body, a cover plate, a locking mechanism, an exhaust mechanism, etc. The front side of the right part of the fumigation box body is rotatably connected with a cover plate, and a locking mechanism is provided on the cover plate. An exhaust mechanism is arranged inside the fumigation box body. In the present invention, the telescopic end of the electric push rod drives the locking frame to slide, so that the locking frame is clamped with the adjacent locking sleeve, thereby locking and fixing the cover plate. At the same time, the concentration of methyl bromide gas in the fumigation box body is detected in real time, and the methyl bromide gas in the fumigation box body is pumped by the air extraction pump and discharged upward through the ventilation pipe to realize the internal circulation flow of the methyl bromide gas.

The utility model relates to the technical field of methyl bromide fumigation, and discloses a constant-temperature methyl bromide fumigation all-in-one machine which comprises a fumigation box, the front side of the fumigation box is rotationally connected with a box door, the top end of the interior of the fumigation box is fixedly connected with a heater, and the top end of the fumigation box is fixedly connected with a fumigator. Four limiting columns are fixedly connected to the interior of the fumigation box, three placing frames are slidably connected to the outer sides of the four limiting columns, an adjusting toothed plate is fixedly connected to the interior of the fumigation box, an adjusting seat is fixedly connected to the bottom end of the heater, and a pressing plate is slidably connected to the interior of the adjusting seat; and two driving strips are rotationally connected into the pressing plate. According to the fumigation device, the clamping plate is clamped with different teeth on the adjusting toothed plate, so that the distance between the placing frames can be adjusted, a large number of objects are prevented from being stacked, methyl bromide can be more uniformly distributed on the surface of each object, the treatment effect difference is reduced, and the fumigation effect is improved.

This utility model discloses a fruit fumigation and preservation device, relating to the field of fruit preservation technology. It includes an outer casing with an array of tray structures slidably connected within it. A pneumatic device is installed within the tray structures, and a corresponding braking structure is installed within the outer casing. This utility model introduces methyl bromide gas into an installation pipe via an air inlet pipe. The accumulation of the methyl bromide gas causes the sliding pipe to slide upwards, which in turn compresses the movable top cover to slide upwards. The methyl bromide gas in the sliding pipe then flows through the air outlet into the fruit tray and its frame. Due to the relatively large molecular weight of methyl bromide gas, it accumulates at the bottom of the fruit tray. As the methyl bromide gas accumulates, it forces air outwards through the gap between the tray frame and the movable top cover, ensuring sufficient contact between the methyl bromide gas and the fruit, thereby reducing the consumption of methyl bromide gas.

This invention provides a method for preparing deuterated paraoxymethylene. Specifically, this invention provides a method for preparing deuterated paraoxymethylene comprising the following steps: (S1) deuteration of dibromomethane; (S2) synthesis of deuterated methylene diacetate; and (S3) synthesis of deuterated paraoxymethylene.

Electronic-grade bromotrichloromethane, a preparation method therefor, and a use thereof. The preparation method for the electronic-grade bromotrichloromethane comprises the following steps: mixing a bromotrichloromethane raw material with a 13X molecular sieve for adsorption, and filtering the mixture to obtain a filtrate; and subjecting the filtrate to distillation treatment under atmospheric pressure, and sequentially collecting a first fraction and a second fraction, wherein the second fraction is the electronic-grade bromotrichloromethane; and the mass of the first fraction is 12-18% of the mass of the filtrate, and the mass of the second fraction is 65-75% of the mass of the filtrate. By means of the preparation method for electronic-grade bromotrichloromethane, bromotrichloromethane having higher purity can be prepared.

The invention discloses a method for extracting and converting bromine ions dissolved in a water body and detecting stable bromine isotopes, and belongs to the field of isotope detection methods. The method comprises the following steps: oxidizing bromide ions in a water body by using acidic sodium dichromate based on the oxidation-reduction characteristic of the bromide ions in the water body to obtain bromine gas, reacting the bromine gas with an alkaline solution to obtain sodium bromide, adding silver ions into the solution to generate silver bromide precipitates, drying the precipitates, quantitatively putting the precipitates into a jaw headspace bottle in a dark environment, and adding methyl iodide; reacting under optimized conditions to generate methyl bromide gas; a gas isotope mass spectrometer and a gas chromatograph which are provided with receiving cups with the mass numbers of 94 and 96 are used in a combined mode, interference of impurity gas is eliminated through modified Isolink II equipment, after bromomethane mixed gas is separated through a chromatographic column, the impurity gas is emptied, bromomethane enters the mass spectrometer, and the bromine isotope ratio is accurately measured. The method can be used for evaluating and researching sources, causes and formation hydrogeochemical and physical processes of oil field water, underground brine, salt water and the like.

The invention relates to the technical field of medicine refining, in particular to a process for reducing the content of genotoxic impurities in a fluticasone propionate raw material medicine. The process comprises the following steps: S1, reacting a compound I with bromofluoromethane in DMF (Dimethyl Formamide) under an alkaline condition, and adding an adsorbent into an obtained reaction solution; stirring at controlled temperature for a period of time, and filtering at low temperature to obtain fluticasone propionate filtrate; and S2, controlling the temperature at 0-10 DEG C, dropwise adding 1-1.5 mol of hydrochloric acid into the fluticasone propionate filtrate to adjust the pH value and deionized water, filtering, and drying to obtain the fluticasone propionate with reduced genotoxic impurity content. The process for reducing the content of the genotoxic impurities in the fluticasone propionate raw material medicine is simple and convenient to operate and low in cost, not only can reduce the harm of excessive bromofluoromethane to operators, but also greatly reduces the harm of the bromofluoromethane volatilized into the air to the environment, and is very suitable for large-scale industrial application.

The invention discloses a kind of synthetic method of 6-trifluoromethylthiophenanthridine compounds, belong to the field of organic synthesis technology.The present invention uses phenanthridinethione as raw material, with cheap and easily available trifluorobromomethane as fluorination reagent, under the action of visible light induction and photocatalyst and alkali, by the free radical addition reaction of C=S, prepares the phenanthridine compounds containing trifluoromethylthio in one step.The method has the characteristics of green safety, cheap and easy to obtain raw materials, high atom economy, good regioselectivity of reaction, mild reaction conditions, wide application range of substrate, high yield and easy purification of product, belongs to green synthesis.

The utility model provides a movable fumigating, dosing and vaporizing device, which belongs to the technical field of fumigating treatment devices and comprises a box body, a weighing platform and a heater are arranged in the box body, a steel cylinder fixing frame is arranged above the weighing platform, the heater is provided with a medicament input port and a medicament output port, the medicament input port is communicated with a feeding hose, and the feeding hose is communicated with the feeding hose. The feeding end of the feeding hose is connected with a three-way connector, one connector of the three-way connector is connected with a steel cylinder connector, and the other connector of the three-way connector is connected with a purging assembly. And the medicament output port is connected with an air outlet pipeline. When the device is used for performing methyl bromide fumigation treatment on the fumigation storehouse, on one hand, the device can ensure that methyl bromide can achieve a qualified fumigation dosing vaporization effect by adjusting the heater; and on the other hand, the weight of the steel cylinder can be weighed in real time through the weighing table, so that the purpose of accurately applying the pesticide can be achieved.

The present application relates to a preparation method of monofluoromethane, the preparation method comprises the following steps: (1) mixing halogenated methane, iodide and organic solvent, and reacting to obtain an organic solution of methyl iodide; the halogenated methane comprises liquid monochloromethane and / or monobromomethane; (2) mixing fluoride, a promoter and the organic solution of methyl iodide obtained in step (1), and reacting to generate gaseous product monofluoromethane. The preparation method provided by the present application does not require the use of a catalyst, and the organic solvent can be reused, thereby reducing production costs; the preparation method provided by the present application is simple to operate, the product quality is stable, the purity is high, and is suitable for continuous production.

The invention provides a preparation method of deuterated paraformaldehyde. Specifically, the invention provides a preparation method of deuterated polyformaldehyde, which comprises the following steps: (S1) deuterating dibromomethane; (S2) synthesis of deuterated methylene diacetate; and (S3) synthesizing the deuterated polyformaldehyde.

The invention discloses a photoacoustic spectrometry fumigation gas concentration analysis system, and relates to the technical field of fumigation operation. The system comprises a system cabinet, a fumigation gas concentration analysis module which is arranged in the system cabinet and detects the concentration of methyl bromide gas based on a photoacoustic spectrum principle, and an environmental parameter detection module which is arranged in the system cabinet. According to the invention, based on a photoacoustic spectrum principle, an active temperature control and real-time humidity digital compensation mechanism is combined, so that the defects that a traditional sensor is easily influenced by environmental temperature and humidity and has cross interference and drift are fundamentally overcome, and the accuracy and stability of data in a full range are ensured; the equipment cabinet with the IP54 protection level guarantees long-term stable operation of internal elements in a severe industrial environment, the unique multi-step triggering process of calibration, temperature control, humidity judgment and detection ensures that measurement is automatically carried out under the optimal condition, and personal errors are reduced.

The application discloses a 2-trifluoromethyl-3-amino indole compound and a preparation method thereof, and belongs to the technical field of organic synthesis. The preparation method of the 2-trifluoromethyl-3-amino indole compound comprises the following steps: under the action of visible light induction and a tertiary amine organic base, free radical cascade cyclization reaction of CF3Br and an aryl isonitrile derivative is carried out in an organic solvent to obtain the 2-trifluoromethyl-3-amino indole compound. The application firstly proposes a method for preparing the 2-trifluoromethyl-3-amino indole compound in one step, which uses the aryl isonitrile derivative as a raw material, uses CF3Br as a trifluoromethylating reagent, and under the action of visible light induction and the tertiary amine organic base, free radical cascade cyclization reaction of trifluorobromomethane and the aryl isonitrile derivative is carried out. The raw material is cheap and easy to obtain, no noble metal photosensitizer needs to be added, the operation is simple, the reaction condition is mild, the reaction is green and safe, the reaction yield is good and the like, and the method has good application value.

The present invention discloses a method for synthesizing tetrahydropyridazine compounds, belonging to the technical field of organic synthesis. CF3Br and N-allyl-N-acylhydrazone undergo a radical tandem cyclization reaction under visible light induction in an organic solvent in the presence of a photocatalyst and a basic reagent. The reaction mixture is concentrated and purified by column chromatography to obtain the tetrahydropyridazine compounds. The present invention for the first time uses trifluorobromomethane in the radical amino-fluorination reaction of olefins to construct tetrahydropyridazine compounds. CF3Br is an industrial raw material that is non-toxic, odorless, inexpensive, and easily available. Compared with other fluorination reagents, it has a low price, is easily obtained, and has high atom economy.

The present invention discloses a method for synthesizing 3-trifluoromethyl chromone compounds, and belongs to the field of organic synthesis technology. The steps of the synthetic method include: dissolving 2-hydroxyaryl enamine ketone compounds, photocatalysts, and alkali in an organic solvent, passing CF3Br gas, and reacting under 390-460nm blue light irradiation to obtain 3-trifluoromethyl chromone compounds. The present invention discloses for the first time the free radical tandem cyclization reaction of cheap and easily available trifluorobromomethane and 2-hydroxyaryl enamine ketone compounds to synthesize 3-trifluoromethyl chromone compounds, and provides a new method for the synthesis of 3-trifluoromethyl chromone compounds. In the presence of a photocatalyst, trifluorobromomethane generates trifluoromethyl radicals, and the intramolecular hydroxyl group serves as an intermediate capture group. The trifluoromethyl radicals and carbon-carbon double bonds are added in series with C / O bond cyclization, and then the 3-substituted chromone can be synthesized in one step by removing the small molecule amine.

The invention discloses a 2-trifluoromethyl-3-amino indole compound and a preparation method thereof, and belongs to the technical field of organic synthesis. The preparation method of the 2-trifluoromethyl-3-aminoindole compound comprises the following step: under the existence of visible light induction and tertiary amine organic alkali, CF3Br and an aryl isonitrile derivative are subjected to a free radical tandem cyclization reaction in an organic solvent, and the 2-trifluoromethyl-3-aminoindole compound is obtained. The invention provides a method for preparing the 2-trifluoromethyl-3-aminoindole compound in one step by taking the aryl isonitrile derivative as a raw material and CF3Br as a trifluoromethylation reagent through free radical tandem cyclization reaction of bromotrifluoromethane and the aryl isonitrile derivative under the action of visible light induction and tertiary amine organic alkali for the first time. The method has the characteristics of cheap and easily available raw materials, no need of adding a noble metal photosensitizer, simplicity in operation, mild reaction conditions, greenness, safety, good reaction yield and the like, and has a very good application value.

The invention discloses a synthetic method of a clarithromycin preparation promoted by ionic liquid and the clarithromycin preparation. The synthetic method comprises an etherification reaction, a silanization reaction and a methylation reaction. The etherification reaction comprises the following steps: adding erythromycin A-9-oxime into a reaction container, and adding ionic liquid [Bmim] BF4 as a reaction solvent. The silanization reaction comprises the following steps: adding 1, 1, 1, 3, 3, 3-hexamethyl disilazane and imidazole into a reaction container containing an etherification reaction result feed liquid of the [Bmim] BF4 reaction solvent. The methylation reaction comprises the step of adding methyl bromide and potassium hydroxide into a reaction container containing silanization reaction result feed liquid of the [Bmim] BF4 reaction solvent. The three-step reaction of etherification, silanization and methylation is carried out in the same reactor, and products in all steps do not need to be separated, so that a continuous process is realized. The ionic liquid as a reaction solvent is non-volatile and non-flammable, and is an important path for realizing green synthesis and clean production.

The present invention relates to an insulating flame-retardant automatically fire-extinguishing patch and a preparation method therefor. The insulating flame-retardant fire-extinguishing patch comprises a bottom film, an adhesive layer and an insulating flame-retardant layer, wherein the insulating flame-retardant layer comprises: 20-60 parts of perfluoro-2-methyl-3-pentanone microcapsules, 20-30 parts of polydimethylsiloxane, 0.1-5 parts of magnesium hydroxide, 0.1-5 parts of triphenyl phosphate, 0.5-5 parts of tributyl phosphate, 0.1-5 parts of tris(2-ethylhexyl)phosphate, 0.2-5 parts of tris(2,3-dichloropropyl)phosphate, 0.2-5 parts of a tetrabromobisphenol A epoxy resin, 0.5-3 parts of antimony trioxide, 0.1-5 parts of a borate, 0.1-5 parts of dibromochloromethane, and 0.1-5 parts of trichlorobromomethane. The insulating flame-retardant fire-extinguishing patch of the present invention is easy to install, does not require maintenance, actively extinguishes a fire in the incipient stage, can achieve the effect of repeated fire extinguishing and effectively prevent reignition and fire expansion, and is safe, green and environmentally friendly.

The invention discloses a 3-trifluoroalkyl quinoxaline-2 (1H)-ketone compound and a preparation method thereof, and relates to the technical field of organic synthesis. The invention provides a method for preparing a 3-trifluoroalkyl quinoxaline-2 (1H)-ketone compound by taking bromotrifluoromethane as a trifluoromethyl reagent through three components of bromotrifluoromethane, 1-methylquinoxaline-2 (1H)-ketone and olefin by a one-pot method in one step under the action of visible light induction and amidine organic alkali. According to the preparation method provided by the invention, the derivatives of ibuprofen and naproxen are synthesized for the first time. The preparation method disclosed by the invention has the characteristics of cheap and easily available raw materials, no need of adding a noble metal photosensitizer, simplicity in operation, mild reaction conditions, greenness, safety, excellent reaction yield and the like.

The invention relates to the technical field of medicine synthesis, in particular to a pyridostigmine bromide synthesis method which is completed in two steps, the first step of 3-dimethylaminoformyloxy pyridine synthesis is consistent with a traditional synthesis method, and the second step of pyridostigmine bromide synthesis is consistent with a traditional synthesis method. A methylation process and a bromination process are different, 3-dimethylamino formyloxy pyridine is methylated by adopting dimethyl sulfate, and then ammonium bromide is added to form salt, so that a highly toxic product triphosgene or bromomethane is not needed in the whole process, and the method is green, environment-friendly and more suitable for industrial production, and solves the problem that the synthesis process of existing pyridostigmine bromide is difficult to carry out when pyridostigmine bromide is synthesized. The technical problems that in the prior art, the adopted highly toxic product triphosgene is not suitable for commercial production, and adopted bromomethane is gas at normal temperature, is liquefied and stored in a commonly used steel cylinder in industry and is inconvenient to use are solved, meanwhile, the total yield of the synthesized pyridostigmine bromide can reach 80% or above, and the wastewater generation amount is greatly reduced.

The application discloses a kind of anhydrous liquid for low-dimensional material anhydrous wet transfer and its application, anhydrous liquid includes 60% to 100% component A and 0 to 40% component B by mass percentage, component A includes one or more of tribromomethane, formamide, phenol, glycerol, methylpyrrolidone, quinoline, component B includes one or more of acetone, ethanol, isopropanol, anisole, chloroform, toluene.Formation support layer on the surface of low-dimensional material on substrate, after separation from substrate, transfer to anhydrous liquid protected by inert gas atmosphere, with target substrate from anhydrous liquid, remove support layer to realize the transfer of low-dimensional material.Widen the scope of application of wet transfer, there is no limit to substrate material, especially suitable for surface easily with water or oxygen adsorption, dissolution or reaction material, realize the preparation of low-dimensional material high mobility field effect transistor, high quality van der waals heterojunction longitudinal diode, lay the foundation for the development of high-frequency, high-speed electronic devices and circuits.