7 results about "Halobenzene" patented technology

This invention relates to an industrial preparation method for 2-methylphenylacetic acid, comprising the following steps: under an inert solvent, 2-methylhalobenzene and malonate diester undergo a coupling reaction in the presence of a catalyst and base A to obtain compound one; compound one is hydrolyzed and decarboxylated under the presence of base B to prepare 2-methylphenylacetic acid; the chemical structural formula of compound one is: [formula missing], where R is a C1-C8 alkyl group. Compared with existing technologies, this invention uses inexpensive raw materials, is simple to operate, can react under normal pressure, has relatively mild conditions, is safe and environmentally friendly, and is easy to industrialize.

The invention relates to a preparation method of aldehyde group functionalized halogen-containing helicene, which comprises the following steps: S1, dissolving terephthalaldehyde and p-halobenzyl cyanide in ethanol, adding sodium ethoxide into the solution for reaction, and washing, filtering and drying a reaction product to obtain a solid A; s2, dissolving the solid A in methylbenzene, then adding iodine and epoxypropane for reaction, and washing, filtering and drying a reaction product to obtain a solid B; s3, dissolving the solid B in dichloromethane, adding n-butyllithium into the dichloromethane, sequentially and slowly adding methanol, water and hydrochloric acid after the color of the solution is changed, extracting an organic filtrate after the reaction is completed, carrying out rotary evaporation on the organic filtrate, washing, filtering and drying to obtain aldehyde group functionalized halogen-containing helicene; the invention provides the aldehyde group functionalized halogen-containing helicene and the preparation method thereof, the method is simple to operate, the reaction is simple and convenient, the expansion is flexible, the aldehyde group is successfully introduced into the compound, the reaction steps are reduced, and the experiment complexity is reduced.

The invention belongs to the technical field of high-performance special materials, and discloses a one-step method for preparing silicon alkyne resin MDPES. The method comprises the following steps: mixing 2-halophenylacetylene, dichlorosilane and a solvent, adding magnesium, and heating for reaction; after the reaction is finished, adding acid liquor for neutralization, and then extracting and layering to obtain an organic layer; then concentrating the organic layer to obtain a concentrated solution, and finally carrying out molecular distillation on the concentrated solution to prepare the silicon alkyne resin MDPES. Wherein the 2-halogen phenylacetylene comprises one of 2-iodine phenylacetylene, 2-bromophenylacetylene and 2-chlorophenylacetylene; and the molecular formula of the dichlorosilane is R1R2SiCl2. According to the method provided by the invention, the 2-halophenylacetylene and the dichlorosilane are subjected to one-step reaction in the anhydrous solvent to prepare the product with high purity and high yield. The method uses few raw materials, the preparation steps are simple, and the production efficiency is high; and the prepared product has the advantages of high yield, high purity, safety, environmental protection and easiness in industrialization.

This invention provides an efficient method for preparing halogen-doped graphene quantum dots, comprising the following steps: adding 1,3,6-trinitropyrene to a polytetrafluoroethylene reactor, adding a halobenzene solvent, ultrasonically dispersing the mixture, and then carrying out a solvothermal reaction. After the reactor cools to room temperature, the solvent is removed by a rotary evaporator, finally obtaining graphene quantum dot powder. Using halobenzene as both solvent and dopant source enables one-step completion of doping and synthesis, avoiding the need for additional dopants and catalysts. The reaction system is simple, the process flow is greatly simplified, and the preparation cycle is significantly shortened.

The invention discloses a preparation method of 3-halogenated alkyl-1-methyl-1H-pyrazole-4-carboxylic ester, which is characterized in that 5-halogenated alkyl-1-methyl-1H-pyrazole-4-carboxylic ester is used as a raw material, and the 3-halogenated alkyl-1-methyl-1H-pyrazole-4-carboxylic ester is synthesized by a transposition reaction in the presence of phosphotriester and a trifluoromethyl halogenated benzene compound. According to the method, the trifluoromethyl halogenated benzene compound is used as the catalyst, the boiling point of the trifluoromethyl halogenated benzene compound is low, obvious ionization is not generated in the reaction process, the trifluoromethyl halogenated benzene compound and the unreacted raw material 5-halogenated alkyl-1-methyl-1H-pyrazole-4-carboxylic ester can be steamed out together, and the steamed-out raw material 5-halogenated alkyl-1-methyl-1H-pyrazole-4-carboxylic ester is directly used for next reaction; extra post-treatment steps such as extraction and water washing are not needed, the post-treatment steps are simplified, introduction of exogenous acid is avoided, and the production and post-treatment cost is reduced.

This invention relates to the field of biphenyl synthesis technology and discloses a method for preparing substituted biphenyls. The method for preparing substituted biphenyls provided by this invention includes: in the presence of a mixed solvent and a base, and in the presence of a catalyst and a ligand, a halobenzene compound and a phenylboronic acid compound undergo a coupling reaction to obtain a coupling reaction product. The catalyst is selected from palladium catalysts, the ligand is selected from ferrocene compounds, and the mixed solvent is water and a water-immiscible organic solvent or water and an alcohol solvent. According to the method of this invention, the amount of catalyst used is small, the operation is simple, the amount of waste is small, and the yield is significantly improved.

The invention discloses a preparation method of 1-(1, 1-dimethyl propoxy)-4-vinyl benzene, and belongs to the technical field of organic synthesis. The method comprises the following steps: firstly, taking p-fluorohalobenzene (p-fluorobromobenzene or p-fluorochlorobenzene) and tert-amyl alcohol alkali metal salt (potassium tert-amyl alcohol or sodium tert-amyl alcohol) as raw materials, carrying out etherification reaction at 120-160 DEG C under the action of a copper catalyst, and separating and purifying to obtain an intermediate 1 (1-(1, 1-dimethyl propoxy)-4-halobenzene); then, carrying out Suzuki coupling reaction on the intermediate 1 and vinylboronic acid pinacol ester in the presence of a palladium catalyst / phase transfer catalyst, potassium carbonate and a reaction aid (potassium fluoride, sodium fluoride, cesium fluoride or lithium fluoride) at 78-100 DEG C, and separating and purifying to obtain a high-purity target product. The method disclosed by the invention has the advantages of easily available raw materials, mild reaction conditions, simplicity and convenience in operation, high yield, good product purity and suitability for industrial production.