166 results about "Tetra-n-butylammonium bromide" patented technology

A process for preparing cyclic carbonate features that catalytic cycloaddition reaction of CO2 on epoxy compound at 100-140 deg.C and 1.5-4.5 MPa for 4-8 hrs under the existance of the catalyst whichis composed of azacyclic compound (halogenated alkylpyridine or halogenated 1,3-dialkyl imidazole) and non-metal halide, and the cocatalyst which is alkali-metal halide or ammonium tetrebutyl bromide. Its advantages are high catalytic activity, smooth reaction condition, easy separation of resultant from catalyst, and cyclic use of catalyst.

The invention relates to a gastrodin synthesizing method, which can effectively solve the preparation problem of gastrodin to meet the requirements of the gastrodin in pharmaceuticals. The method comprises the steps of adding catalyst perchloric acid, acetylating anhydrous dextrose by using acetic anhydride to produce per-acetyl dextrose, feeding hydrogen bromide to bromizing hemiacetal hydroxyl of the per-acetyl dextrose to produce bromo-tetraacethyl glucose, further and dropwise adding a bromo-tetraacethyl glucose solution into chloroform and tetrabutyl ammonium bromide, carbonate and para hydroxybenzene in water to obtain 4-formyl benzene-2', 3', 4', 6'- tetraacetyl-beta-D-glucopyranose, performing re-crystallization with ethanol, adding raney nickel or palladium and carbon, feeding hydrogen and pressurizing to hydrogenate, performing filtering, adding sodium alcoholate or ammonia in to filtrate to perform protecting group removal until the reaction is finished completely, performing pressure reduction and concentration to obtain crude gastrodin, and re-crystallizing the crude gastrodin by using alcohol or an alcohol and ester solvent or an alcohol and ketone solvent to obtain the gastrodin. The gastrodin synthesizing method is abundant and cheap in raw materials, simple in process, recycled in solvent, small in pollution and high in quality.

The invention relates to a preparation method of an Abamectin B2a fine powder. The method comprises the following steps: A, concentrating an Abamectin B1a crystallization mother liquor into a paste state; B, dissolving the obtained paste with sec-butyl acetate, and then adding a tetrabutyl ammonium bromide aqueous solution for washing and layering; C, concentrating the sec-butyl acetate solution subjected to washing and layering, then adding a crystallization solvent for dissolution, naturally cooling to room temperature, crystallizing, and filtering to obtain an Abamectin B2a fine powder crude product; and D, recrystallizing the Abamectin B2a fine powder crude product to obtain the Abamectin B2a fine powder. According to the invention, waste Abamectin crystallization mother liquor is recovered and utilized to extract effective substances; tetrabutyl ammonium bromide aqueous solution is used for washing, which has better impurity removal effect than traditional water washing or saturated brine washing, and makes the solution layer more easily; aromatic hydrocarbon is used as the crystallization solvent; and the content of obtained B2a fine powder is higher than 93%.

The invention discloses 1, 2-anti form glucoside derivative of oxazole compound. During the preparation, 4-(3, 4, 5-trimethoxy phenyl)-5-(3-hydroxyl-4-methoxy phenyl oxazole is used as the acceptor of glycosyl, bromo sugar of D-glucose, D-galactose, L-arabinose, D-xylose, L-fucose or lactose with full acetyl protection, or trichlorine imine ester of L-rhamnose or D-mannose with full acetyl protection is adopted as the donator of glycosyl, glycosylation is performed with the catalysis of alkali and tetrabutyl ammonium bromide or lewis acid, to obtain glucoside derivative containing acetyl protecting group; and then the acetyl protecting group is removed by utilizing methyl alcohol and sodium methoxide, to obtain 1,2 anti-form glucoside derivative of oxazole compound. The preparation method is simple, highly effective and universal, the route is short, the water-solubility of the product is good, the bioavailability is high, thereby the glucoside derivative can be applied as antineoplastic medicine inhibiting microtubule assembly and selectively targeting tumor blood vessels.

The present invention relates to double-component carried catalyst PdCl2-Cu(OAc)2 / zeolite for synthesizing diphenyl carbonate and its preparation. The catalyst consists of zeolite in 50-100 weight portions, PdCl2 in 0.1-10 weight portions and Cu(OAc)2 in 0.1-30 weight protions. It is prepared through equi-volume soaking and roasting at 250-750 deg.c. The catalyst system has also metal acetate as inorganic oxidation-reduction assistant, hydroquinone as organic oxidation-reduction assistant, and tetrabutyl ammonium bride as surfactant. The catalyst has very high catalytic activity and excellent selectivity to liquid phenol in synthesizing diphenyl carbonate. The catalyst is easy to separate from product, easy to recover and regenerate and has simple preparation process.

The present invention provides a method for preparing a submicron all-silicon DD3R molecular sieve. The method comprises the following steps: 1) mixing a silicon source, amantadine, water and an auxiliary template agent to obtain crystal synthesis mother liquor and stirring and ageing the crystal synthesis mother liquor; and 2) adding 0.01-5% by mass of seed crystals into the crystal synthesis mother liquor and heating the crystal synthesis mother liquor with the seed crystals at 120-220 DEG C, wherein the auxiliary template agent is one or more selected from the group consisting of tetramethyl ammonium hydroxide, tetraethyl ammonium hydroxide, tetraethyl ammonium fluoride, tetraethyl ammonium bromide, tetrabutyl ammonium hydroxide and tetrabutyl ammonium bromide. According to the present invention, by adopting the method of mixing the template agent and adding the seed crystals, an induction period in a crystallization process is greatly shortened, a crystallization rate is increased and a synthesis period of the DD3R molecular sieve is shortened, so that the synthesis period of the submicron all-silicon DD3R molecular sieve is shortened from 25 days in the prior art to 3 hours; and the prepared DD3R molecular sieve is uniform in crystal size, has a particle size less than 1 micrometer, has a yield rate close to 100%, and has great application potential in adsorption and separation fields.

The invention provides a preparation method of 2-cyano-4'-bromomethylphenylbenzene, which comprises the following steps: (1) adding 2-cyano-4'-methylphenylbenzene, dibromohydantoin and tetrachloroethylene into a reactor, adding a catalyst, and evenly mixing, wherein the mol ratio of 2-cyano-4'-methylphenylbenzene to dibromohydantoin to tetrachloroethylene to catalyst is 1:(0.5-0.6):(8-12):(0.008-0.012), and the catalyst is tetrabutyl ammonium bromide, cetyl trimethyl ammonium bromide or benzyl triethyl ammonium bromide; (2) heating to react, wherein the reaction temperature is controlled at 60-120 DEG C, and the reaction time is controlled at 4-8 hours; and (3) after the reaction finishes, cooling, filtering, concentrating to recover the tetrachloroethylene, and recrystallizing with methanol or ethanol or isopropanol to obtain the 2-cyano-4'-bromomethylphenylbenzene. The production process provided by the invention has the advantages of high operation safety, simple technique, low cost and high yield.

A hydrate slurry used as the cold carrying medium is prepared from ammonium tetrabutylbromide and water through preheating the hydrate solution, over-cooling, ultrasonic treating to eliminate over-cooling state and generate hydrate slurry quickly, and solid-liquid separation for cyclic use. Its advantages are high flowability and high cold delivering density.

The invention discloses a detection method of minodronic acid by using high performance liquid chromatography. The method includes following chromatogram conditions: employing a mixed solution, which is composed of methanol and an aqueous solution containing sodium acid pyrophosphate and tetra butyl ammonium bromide, as a mobile phase with a volume ratio of the aqueous solution to the methanol ranging from 90:10 to 100:0, wherein the pH value of the aqueous solution is 7.0-8.0, the concentration of the sodium acid pyrophosphate is 0.02-0.04 mol / L and the concentration of the tetra butyl ammonium bromide is 0.272-0.322 g / L; employing octade-cylsilane (ODS) as a packing material, setting a flow velocity of a high performance liquid chromatography instrument to be 0.8-1.2 ml / min, a detection wavelength to be 218-282 nm and a sample size being 5-50 [mu]l. With the detection method, separation degrees, between a main peak and a neighboring impurity peak, in both a to-be-tested sample and a raw material are more than 1.5; and main peak column efficiencies in both the to-be-tested sample and the raw material are more than 3000. The detection method is good in trailing factor and system applicability.

The invention relates to a production process of abamectin fine powder. The production process method comprises the steps: extracting fermentation liquid filter cake with sec-butyl acetate for three times; combining organic-ester-phase extracts, adding tetrabutyl ammonium bromide aqueous solution for washing, and filtering, concentrating filtrate, and cooling and crystallizing to obtain once crude product; and dissolving the once crude product with ethanol, filtering, naturally cooling to room temperature, adding water at a volume ratio of ethanol to water being (7 : 1)-(4 : 1) for dilution crystallization, washing and drying to obtain the abamectin fine powder product. By adopting the method, the abamectin crystal product with higher purity and yield can be obtained; and compared with the traditional methods, the method has the advantages that the crystallizing time is shorter, the repeated crystallizing frequency is reduced and the production cost is low, thereby being a low-cost and high-efficiency production process of the high-purity abamectin fine powder.

The invention discloses a preparation method for a sulfonanilide compound, which comprises the following steps: adding 1-10 parts by mol of an aprotic dipolar solvent into a reactor, raising the temperature of the reactor to 90-136 DEG C while stirring, adding 0.001-0.1 part by mol of a catalyst, stirring the mixture, dropping 1-10 parts by mol of a sulfonated agent and carrying out a sulfonylation reaction for 10-25h at 90-136 DEG C, and cooling, filtering, washing and baking the reaction product, then obtaining the sulfonanilide compound. The catalyst adopted by the invention is triphenylphosphine, polyethylene glycol or crown ether instead of the former expensive catalysts including tetrabutyl amonium bromide and DMF, while the reaction conversion rate is above 99%, the reaction effect is better, the side reactions are less, and high-purity products are obtained in high yield. With simple technique, low cost of catalyst and few side reactions, the invention is suitable for large-scale industrial production.

The invention relates to a method for preparing tetrabutylammonium hydroxide, which is characterized by comprising the following steps of: blending potassium hydroxide and methanol, adding the mixture into mixed solution of tetrabutyl ammonium bromide and the methanol, filtering and precipitating under reduced pressure, and after heating and refluxing, cooling and crystallizing to obtain the finished product of the tetrabutylammonium hydroxide. By the method, the yield of the product is improved; the requirements of the market are met; and the economic benefit and the social benefit of an enterprise are improved.

This invention relates to preparation method of a antiulcer drug. The invention takes pyrmetazole that chemical name is 5 - methoxyl group - 2 - { [ ( 4 - methoxyl group - 3, 5 - dimethyl - 2 - pyridyl) methyl] sulfinyl} - 1 hydrogen - benzimidazole as raw material, takes IBX that chemical name is 1 - hydroxy - 1, 2 - benzene iodine acyl - 3 ( 1 hydrogen) - ketone - 1 - oxide as oxidizer, and takes quaternary ammonium salt compound tetraethyl ammonium bromide or tetrabutyl ammonium bromide as catalyzer, to synthesize antiulcer drug omeprazole. The invention also relates to the according reclaim measure of oxidizer.

In the present invention, under the presence of polar non-proton solvent N-methyl pyrrolidone and phase transfer catalyst ammonium tetrabutyl bromide or polyglycol 6000, anhydrous 1,1,1-trifluoro-2-chloroethane and potassium acetate in molar ratio 1.0-5.0 to 1.0 react at 100-300 deg.c; and through further flash distillation and rectification, 2,2,2-trifluoroethyl acetate is prepared. Compound 2,2,2-trifluoroethyl acetate is the precursor for synthesizing trifluoroethanol as organic refrigerant and the important material for synthesizing fluoric compound. The present invention has the featuresof short reaction period, high material converting rate, high product yield, reuse of the solvent, etc. and may be used in industrial production.

Coating powders having a low curing temperature are comprised of an acid functional acrylic resin having an acid number between about 40 and 220, triglycidyl isocyanurate, and a curing catalyst comprising tetrabutyl ammonium bromide. Such coating powders have a stoichiometry of acid groups to epoxy groups of between about 0.5 and 2.0.Low curing temperature coating powders comprising an acrylic resin, a polyester resin, an epoxy functional crosslinking agent, and a curing catalyst exhibit good flexibility properties following application to a substrate and curing. Good flexibility may also be achieved by incorporating blended epoxy crosslinking agents into acrylic resins alone or into blended acrylic and polyester resins. Such blended crosslinking agents should have an epoxy functionality of from about 2 to about 6 and an equivalent weight of from about 100 to about 700.

The invention discloses a 25,27-di(3-methyl-thio-ethoxy thiadiazole) calix[4]arene stationary phase which is low in cost, high in content of compounded calixarene bonded stationary phase bonded amount, and stable in stability bonding layer, and is prepared by the following steps of: under the action of phase transfer catalyst ammonium tetrabutyl bromide, carrying out nitrogen protection to gamma-glycidol ether bonded silica gel and calixarene derivative sodium phenolate, and preparing the object calixarene stationary phase at 80 DEG C. The calixarene stationary phase compounded by the method in the invention is high in bonded amount, stable in boned layer, simple and easy in compounding method, low in cost, free of pollution in the compounding process and the like. The stationary phase not only has traditional ODS (Octadecylsilyl) reversion phase chromatography performance, and has containing complexing action, pi-pi action, hydrogen bonding action and dipole-dipole action because of many action sites; in a certain degree, the stationary phase in the invention has special separation performance comparing with the traditional ODS column.

The invention discloses a synthetic method of 5-bromo-2-chlorobenzoic acid. The method comprises the following steps of by taking salicylic acid as a starting material, performing bromination reactionto obtain 2-hydroxyl-5-bromo-benzoic acid, and then performing chlorination reaction to obtain the 5-bromo-2-chlorobenzoic acid, wherein a bromination system adopted by the bromination reaction is tetrabutyl ammonium bromide / oxygen / sodium metavanadate, a catalyst is aluminium tribromide, and a solvent is 1,4-dioxane; and a chlorinating agent is carbon tetrachloride, and a catalyst is molybdenum hexacarbonyl. The method provided by the invention adopts the cheap salicylic acid which is wide in source as the starting material and prepares the 5-bromo-2-chlorobenzoic acid through two-step reaction of bromination and chlorination, is novel in synthetic route, relatively low in production cost, relatively small in environmental pollution and very suitable for industrial mass production. According to the method, through the bromination reaction and the chlorination reaction, by selecting proper reagents, relatively high reaction yield and product purity can be obtained.

The invention relates to a method for preparing tetrabutyl ammonium bromide, which is characterized by comprising the following steps of: (1) performing the synthetic reaction of the tetrabutyl ammonium bromide; (2) preparing a crude product of the tetrabutyl ammonium bromide; and (3) refining. The method improves the product yield, meets the requirement of the market and improves the economic benefit and the social benefit of enterprises.

The invention discloses a method for synthesizing di-[propyltriethoxysilane]-tetrasulfide, which comprises the following steps of: (1) mixing and stirring water, sodium sulfide, sodium hyposulfate, elemental sulfur and diethyl hydroxylamine, pumping n-amylamine and isobutylamine into the mixture under the vacuum degree of 0.04 to 0.06MPa, and reacting the mixture for 20 to 40 minutes at the temperature of between 30 and 50 DEG C; (2) adding dodecyltrimethylammonium chloride, tetrabutyl ammonium bromide and hydroxy pyridine into the reaction solution obtained in the (1) under normal pressure, stirring the solution, then adding gamma-chloropropyltriethoxysilane into the solution, reacting the solution for 30 to 60 minutes at the temperature of between 40 and 50 DEG C, continuously reacting the solution for 60 to 80 minutes at the temperature of between 60 and 80 DEG C, filtering the oil phase, and pumping the filtrate into a distillation still; and (3) distilling the filtrate in the distillation still under the vacuum degree of more than or equal to 0.096MPa at the temperature of less than or equal to 160 DEG C when the temperature of the top gas phase is more than 108 DEG C to obtain a product Si-69.

The invention provides a catalyst, which comprises a ligand, a cupric compound, an alkaline inorganic compound, a phenol compound and tetrabutyl ammonium bromide, wherein the ligand has a structure shown in a formula (I), wherein R refers to alkyl or halogenated alkyl. The invention provides a method for synthesizing (S)-octopamine, which comprises the following steps of: a) performing reaction on hydroxy benzaldehyde and nitromethane in the presence of the catalyst in the technical scheme to generate an (S)-octopamine precursor; and b) performing hydrogenation reduction reaction on the (S)-octopamine precursor and hydrogen in the presence of a palladium carbon catalyst to generate the (S)-octopamine. The invention also provides a method for synthesizing (S)-N-trans-feruloyloctopamine, which comprises the following step of: performing amidation reaction on the (S)-octopamine and ferulic acid to generate the (S)-N-trans-feruloyloctopamine.

The invention discloses a binary eutectic ionic liquid and a preparation method thereof. The ionic liquid contains imidazole molecules and has a structure formula as shown on the right, wherein MX is tetrabutyl ammonium bromide, choline chloride or 1-ethyl-3-butyl-benzotriazole hexafluorophosphate. The preparation method comprises the following steps: mixing the tetrabutyl ammonium bromide, the choline chloride or the 1-ethyl-3-butyl-benzotriazole hexafluorophosphate with imidazole; heating the mixture to obtain a homogeneous phase colorless liquid; and vacuum-drying the colorless liquid to obtain the ionic liquid. The ionic liquid has good viscosity, electrical conductivity and stable electrochemical window, wherein the viscosity can reach 11.0 cp minimally at a temperature of 70 DEG C; the electrical conductivity can reach 5.2*10Scm maximally at a temperature of 130 DEG C; the stable electrochemical window can reach 3.4V maximally; besides, the preparation method is simple and environmentally-friendly.

The invention provides a cross-linking agent and a crease finishing agent of sucrose glycidyl ether. The molecular formula of the cross-linking agent and the crease finishing agent of the sucrose glycidyl ether is C12+3nH22+4nO11+n, and the structure formula is C12H22O11(CH2CHCH2O)n, wherein n is between 2 and 8, namely each sucrose molecule contains 2 to 8 glycidyls; and the sucrose glycidyl ether cross-linking agent and the crease finishing agent are prepared from sucrose aqueous solution, epoxy chloropropane, tetrabutyl ammonium bromide, sodium hydroxide and other substances through series of processes. The sucrose glycidyl ether has excellent cross-linking and crease finishing effects, can be mixed with milk protein into solution to treat alkaline decrement orlon textile, and can graft the milk protein firmly on the textile. The cross-linking agent and the crease finishing agent and the synthesizing method can enable the fold elastic recovery angle of silk broadcloth to be raised from 220 degrees to 290-300 degrees, and have convenient application and low cost.

The invention provides a third-order nonlinear optical material, namely a tetrabutyl ammonium fullerene ball and a synthesizing method thereof, which belongs to the field of functional materials. The prior inorganic and organic nonlinear optical materials have the problems of easy deliquescence, poor thermal stability, complicated preparation and the like respectively. The molecular formula of the tetrabutyl ammonium fullerene ball provided by the invention is (NH4)18[(C16H36N)4]24[Mo132O372(H2O)72(CH3COO)30].ca.7NH4CH3COO.ca.173H2O. In the method, after {Mo132} and tetrabutyl ammonium bromide are dissolved in water respectively according to the mass ratio of 1 to 42, and are adjusted by acetic acid respectively until the pH value is between 3.5 and 4.5, the {Mo132} and the tetrabutyl ammonium bromide are mixed to obtain the tetrabutyl ammonium fullerene ball. The third-order nonlinear optical material has the advantages of uneasy deliquescence, high thermal stability, larger nonlinear absorption and non-linear refraction coefficient, self-defocusing property and simple preparation.

The invention provides a preparation process for a diethylene triaminepentaacetic acid dianhydride modified polyvinylidene fluoride separation membrane and a resin with solvents of diethylene triaminepentaacetic acid dianhydride, sodium hydroxide, sodium borohydride, tetrabutyl ammonium bromide, p-toluenesulfonic acid, N,N-dimethylacetylamide, polyvinylpyrrolidone and the like as raw materials by utilizing a chemical blending / phase transfer process, which has the advantages of simple operation, uniform blending and the like. In the process, diethylene triaminepentaacetic acid multi-aminopolycarboxylic acid compounds are uniformly blended in the polyvinylidene fluoride separation membrane and the resin; the hydrophilic performance of the polyvinylidene fluoride separation membrane and the resin is improved; the elimination of complexing state heavy metal ions from waste water can be realized by utilizing the polyvinylidene fluoride separation membrane and the resin; the efficiency for purifying drinking water by utilizing the polyvinylidene fluoride separation membrane and the resin is enhanced; the elimination and the recycling utilization of the complexing state heavy metal ions in industrial waste water can be promoted; and the application of the polyvinylidene fluoride separation membrane and the resin in the field of water processing is expanded.

The invention discloses a high-temperature resisting anti-oxidation metallized film which is characterized by being prepared from the following raw materials in parts by weight: 200 parts of isotatic polypropylene, 12-14 parts of polylactic acid, 3-4 parts of tung oil, 1-2 parts of sodium silicate, 1-2 parts of tetrabutyl ammonium bromide, 1-2 parts of yttrium oxide, 2-3 parts of trichlorine ethyl phosphate, 4-5 parts of ester gum, 1-2 parts of turpentine, 4-5 parts of polyisobutene and 5-6 parts of addtivie. The metallized film is simple in machining process, and moreover the film capacitor made of the metallized film is small in contact resistance, small in size and therefore good in product characteristic; a polypropylene capacitor film made of the metallized film has the characteristics of low thermal shrinkage rate and stable property, namely, good high-temperature stability; due to adoption of corona treatment, the pressure resistance of the film is improved, breakdown is prevented, and the service life is long.

The process of synthesizing pentaerythritol allyl ether as cross-linking agent for polymerization includes the following steps: mixing allyl chloride, alkali catalyst and pentaerythritol in the molar ratio of 3.0-5.5 to 3.0-5.5 to 1.0; etherification reaction at 60-80 deg.c for 8-10 hr under the action of phase transfer catalyst; neutralizing, water washing, desalting and filtering, degassing and refining. The phase transfer catalyst is one of ammonium tetrabutyl bromide and PEG200-PEG1000; and the alkali catalyst is sodium or potassium hydroxide in the concentration preferably of 30 %-50 %. The synthesis process has effectively raised reaction selectivity and produce yield, and the yield may reach 88 % accounting in allyl chloride.

A heat-storage agent which can store a large quantity of cold heat in the temperature range of 3-15 DEG C, is highly effective in preventing supercooling, and can retain the supercooling-preventing effect even when hydrate solidification / melting is frequently repeated. Also provided are: an aqueous solution which enables the formation of a clathrate hydrate serving as a major component of the heat-storage agent; and a process for producing the clathrate hydrate. The aqueous solution contains at least one of tetra-n-butylammonium bromide and tri-n-butyl-n-pentylammonium bromide as a solute and contains tetraisopentylammonium bromide as a supercooling inhibitor, the weight proportion of the tetraisopentylammonium bromide to the tetra-n-butylammonium bromide and / or tri-n-butyl-n-pentylammonium bromide being in a given range. This aqueous solution is cooled to or below a hydrate formation temperature to thereby produce a clathrate hydrate. The heat-storage agent contains this clathrate hydrate as a major component.

The process of synthesizing pentaerythritol allyl ether as cross-linking agent for polymerization includes the following steps: mixing allyl chloride, alkali catalyst and pentaerythritol in the molar ratio of 3.0-5.5 to 3.0-5.5 to 1.0; etherification reaction at 60-80 deg.c for 8-10 hr under the action of phase transfer catalyst; neutralizing, water washing, desalting and filtering, degassing and refining. The phase transfer catalyst is one of ammonium tetrabutyl bromide and PEG200-PEG1000; and the alkali catalyst is sodium or potassium hydroxide in the concentration preferably of 30 %-50 %. The synthesis process has effectively raised reaction selectivity and produce yield, and the yield may reach 88 % accounting in allyl chloride.

The present invention provides carried non-mobile metal compound catalyst Cu(OAc)2 / zeolite for synthesizing diphenyl carbonate and its preparation. The catalyst consists of zeolite in 50-100 weight portions and Cu(OAc)2 in 0.1-30 weight portions. It is prepared through equi-volume soaking and roasting at 250-750 deg.C. The catalyst system has metal acetate as inorganic oxidation-reduction assistant, hydroquinone as organic oxidation-reduction assistant, and tetrabutyl ammonium bridge as surfactant. The catalyst has very high catalytic activity and excellent selectivity to liquid phenol in synthesizing diphenyl carbonate. The catalyst is easy to separate from product, easy to recover and regenerate and has simple preparation process.

The invention relates to a synthesis method for methyl hydrazine, which comprises the following steps: causing hydrazine hydrate and dimethyl sulfate to react at a temperature of 115 and 125 DEG C by using hydrochloric acid as a protecting agent and tetrabutyl ammonium bromide as a catalyst, adding alkali to neutralize and dissociate out the methyl hydrazine, cooling and removing salt, and rectifying the filter liquor to obtain an aqueous solution of the methyl hydrazine. The synthesis method has the advantages of low raw material cost, simple production equipment, quick reaction rate, high yield, and the like.