6 results about "Bromide methyl" patented technology

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.

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.

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.