82 results about "N-Butyllithium" patented technology

The invention belongs to the technical field of organic synthesis and medicinal chemistry, and discloses a total synthesis method of rhododendron heteroterpenin Rhododaurines A-C. The total synthesis method comprises the following steps: carrying out allyl stereoselective addition on a compound 3 and a compound 5 in a toluene solvent under the conditions of catalysis of n-butyllithium and low temperature of-78 DEG C, and constructing a chiral center to obtain a compound 6; removing a methoxy methyl (MOM) protecting group from the compound 6 under an acidic condition, cyclizing, and reacting to generate rhododaurine C (7); the rhododaurine C (7) is subjected to intramolecular [4 + 2] cycloaddition and oxidation reaction in the illumination and oxygen atmosphere of 300-385 nm, and rhododaurine B (8) and an epoxy epimer epinedodaurine B (9) are obtained; and carrying out protonation and rearrangement on the epidodaurine B (9) by virtue of acid catalysis cyclic ether, so as to generate the rhododaurine A (10). The method can overcome the defects that the content of rhododendron miscellaneous terpenoids Rhododaurines A-C in nature is extremely low, and large-scale extraction is difficult.

The invention discloses a synthesis method of a novel benzosuberone compound, and belongs to the field of organic synthesis. The preparation method comprises the following steps: uniformly stirring methyltriphenylphosphonium bromide in a solvent at room temperature, dropwise adding an n-hexane solution of n-butyllithium in an ice-water bath, stirring a reaction system at room temperature for 30-40 minutes after dropwise adding is completed, then adding an initial raw material phenanthrenequinone 1 in the ice-water bath, transferring the reaction system to 40 DEG C for reaction, and after the reaction is monitored to be complete by a TLC (Thin Layer Chromatography) dot plate, filtering, washing and drying to obtain the phenanthrenequinone 1. And pouring the reaction liquid into a silica gel chromatographic column, and simply filtering by using dichloromethane as an eluent to remove salt and phosphine oxide. And performing rotary evaporation to remove the organic solvent to obtain a crude product, and separating and purifying to obtain a target product 2. The method is short in reaction time and low in reaction cost, provides a practical method for obtaining the seven-membered rigid ring skeleton, and has potential value for synthesis of natural products and bioactive molecules.

The invention discloses chain end modified liquid rubber, mixed rubber, a preparation process, a tire and a vehicle, and belongs to the technical field of liquid rubber and manufacturing thereof. According to the liquid rubber, butadiene monomers and a chain transfer agent are added in batches in the preparation process, negative ion active centers are frequently transferred to the chain transfer agent from the tail end of a polybutadiene-based lithium active chain to form new initiation growth centers, then newly introduced butadiene monomers are initiated to grow, the dosage of an n-butyllithium initiator is remarkably reduced, and the stability of the liquid rubber is improved. The production cost is greatly reduced, the generation of sewage is greatly avoided, the monomer concentration of the final rubber product can reach about 80 percent by weight, the productivity is improved, and large-scale production is facilitated; the rubber also enables the filler to have good dispersibility, and has good compatibility with base rubber such as styrene butadiene rubber, natural rubber and the like.

The utility model provides an n-butyllithium taking bottle which comprises a bottle body and a bottle cap and is characterized in that the bottle body is composed of an inner layer structure and an outer layer structure, an air inlet pipe and a liquid outlet pipe are arranged on the bottle cap, an air inlet valve is arranged on the air inlet pipe, a liquid outlet valve and a buckle are arranged on the liquid outlet pipe, and the liquid outlet pipe and a feeding pipe are connected through the buckle. And an air bag and a feeding needle are arranged on the feeding pipe. The n-butyllithium taking device is connected with an air inlet and liquid outlet device, so that the n-butyllithium taking device is safer when n-butyllithium is taken. When the n-butyllithium bottle topples over or falls off accidentally, the two-layer structure can protect the bottle body from being broken, reagents in the bottle are not prone to being leaked, and accidents are reduced.

The invention relates to a method for preparing (cyclopentadienyl) tris (dimethylamino) hafnium by using nuclear magnetic control, which comprises the following steps: S1, carrying out heating reflux reaction on hafnium tetrachloride, cyclopentadiene and dimethylamine in the presence of n-butyllithium and n-hexane, and after reacting for a certain time, taking supernate to detect a nuclear magnetic hydrogen spectrum; s2, calculating the ratio a of the integral area of the characteristic peak A to the integral area of the characteristic peak B according to the nuclear magnetic hydrogen spectrum, judging whether a is in a target range or not, if a is in the target range, terminating the reaction, separating a liquid phase, distilling and collecting a crude product; and if a value is greater than the maximum value of the target range, adding cyclopentadiene into the reaction system to continue the reaction, and if a value is less than the minimum value of the target range, continuing the reaction until the ratio of the integral area of the characteristic peak A to the integral area of the characteristic peak B in the nuclear magnetic hydrogen spectrum of the reaction supernatant is within the target range, terminating the reaction, separating the liquid phase, distilling and collecting a crude product. The method can effectively improve the safety of the production process, the raw material conversion rate and the product purity.

The invention belongs to the technical field of chemical synthesis of semiconductor materials, and particularly relates to a synthesis method of tetra (dimethylamino) titanium, which comprises the following steps: (1) reacting titanium tetrachloride with dimethylamine to generate an intermediate TiClx [N (CH3) 2] 4-x, where x is an integer from 0 to 4; (2) reacting dimethylamine with an organic metal lithium reagent to synthesize lithium dimethylamino (LiN (CH3) 2); and (3) reacting the intermediate obtained in the step (1) with lithium dimethylamino obtained in the step (2) to obtain tetra (dimethylamino) titanium. By adopting a step-by-step reaction strategy, the dependence on expensive n-butyllithium is fundamentally reduced, the raw material cost is remarkably reduced, meanwhile, the reaction process is optimized by generating an intermediate, the product yield is greatly improved, the generation of byproducts is effectively reduced, and the product purity is improved.

This invention relates to a simple method for modifying β-ketoimine ligand precursors, wherein L... Ph The reaction involves a lithium compound with H2 solution; then a haloalkane is added for C-C coupling; followed by the addition of an acid solution to complete the modification of the β-ketoimine ligand precursor, yielding a terminally alkylated ketoimine. This invention relates to a simple method for modifying β-ketoimine ligand precursors, specifically involving the removal of the proton at the α-position of the β-ketoimine ligand precursor from commercially available n-butyllithium to form a deprotonated β-ketoimine lithium compound, followed by C-C coupling to achieve alkylation at the α-position of the ketocarbonyl group, thus providing a convenient modification of the β-ketoimine ligand precursor.

The application discloses a preparation method of triethyl indium, and relates to the technical field of metal organic source synthesis, wherein a commonly used indium source is mainly trimethyl indium; the trimethyl indium is in a solid state at normal temperature, and is easy to cause the solid indium source to be easy to be hardened and to have excessive residues; when the solid indium source is used in a machine, the concentration output stability is worse than that of a liquid source; the liquid indium source will become an important indium source in the future; the operation method of the triethyl indium in preparation is more complicated; and the purity of the triethyl indium prepared by purification cannot reach a better ideal state. In the application, n-butyllithium and ethyl iodide are reacted under the protection of inert gas, then the reaction product is reacted with indium chloride to generate triethyl indium; the whole operation is simple, raw materials are easy to obtain, and the product has high purity; under the protection of inert gas, the interference of other solution reagents in the preparation process is reduced; therefore, high-quality triethyl indium raw materials can be purified and processed.

The invention discloses a silylene ligand supported metal cobalt catalyst and a preparation method and application thereof, and belongs to the technical field of metal organic catalyst.The preparation method comprises the steps that indole and n-butyllithium serve as raw materials and are subjected to a deprotonation reaction in a tetrahydrofuran solvent at the room temperature, 2-lithium indole is obtained, a tetrahydrofuran solution of chlorosilylene is added at the low temperature, and the 2-lithium indole is obtained; and carrying out nucleophilic substitution reaction at room temperature, and substituting Li in 2-lithium indole with silicon in chlorosilylene to obtain the silylene ligand. The preparation method comprises the following steps: taking a silylene ligand and a cobalt complex as raw materials, carrying out ligand substitution reaction at room temperature in a tetrahydrofuran solvent, and substituting a ligand in the cobalt complex with the silylene ligand to obtain the metal cobalt catalyst supported by the silylene ligand. The prepared metal cobalt catalyst supported by the silylene ligand is used for catalyzing olefin hydrosilylation reaction, ultrahigh catalytic activity is shown, complete conversion of olefin is achieved, Markov products are obtained with excellent selectivity, and therefore the problems of cost and product selectivity in industrial production are solved.

A method for preparing high-purity lithium sulfide by using industrial-grade butyllithium includes the following steps: step A: under an inert gas condition, thoroughly mixing 1.5-2.5 g of lithium chloride, 0.5 L of an industrial-grade n-butyllithium solution (2.5 mol / L) and 1.5-2.5 L of n-hexane to obtain a mixed solution, and charging the mixed solution into a sealed container; step B: under the sealed condition, firstly introducing H2S gas into a gas-washing bottle through a submerged pipe at a rate of 10.5 L / h, then introducing into the mixed solution through the submerged pipe, controlling the reaction temperature at 25-40° C., and continuously stirring for reaction for 4-6 h to obtain a reaction slurry; and step C: under an inert gas condition, filtering the reaction slurry with a G3 sand core funnel to obtain a crude lithium sulfide solid wet material.

The invention provides a kilogram-level preparation method of an organic photoelectric conjugated tin reagent, and belongs to the field of organic synthesis and organic photoelectric materials. The method comprises the following steps: in a dry 20L reaction device, dissolving a conjugated thiophene compound in tetrahydrofuran, keeping nitrogen positive pressure protection, dropwise adding a tetrahydrofuran solution of n-butyllithium and a tetrahydrofuran solution of trimethyltin chloride in a low-temperature reaction system, stirring for reaction, after the reaction is completed, standing for phase splitting, collecting an organic phase, drying, and concentrating filtrate to obtain the conjugated thiophene compound. And recrystallizing to obtain the organic photoelectric conjugated tin reagent. According to the method, efficient macro preparation of various conjugated tin reagents can be achieved, 1-1.2 kg of target products can be prepared through single-batch reaction, and the method has the advantages of being high in yield, easy and convenient to operate, low in cost, good in environmental friendliness and the like.

The invention discloses a kilogram-level preparation method of an organic photoelectric conjugated boron reagent, and belongs to the technical field of organic synthesis and organic photoelectric materials. A kilogram-level preparation method of an organic photoelectric conjugated boron reagent comprises the following steps: uniformly mixing aryl halide and tetrahydrofuran in an inert gas atmosphere to obtain a mixed system 1; placing the mixed system 1 in a liquid nitrogen environment, then dropwise adding a THF solution of n-butyllithium, and stirring to obtain a mixed system 2; and adding a boric acid ester compound into the mixed system 2 for reaction, and finally performing purification treatment to obtain a target product, namely the organic photoelectric conjugated boron reagent. The preparation method of the conjugated boron reagent is efficient, safe and capable of achieving large-scale production, has the advantages of being easy and convenient to operate, low in cost, high in yield, good in purity and the like, is suitable for various benzene series, thiophene, fluorene and other substrates, achieves kilogram-level stable preparation, solves the amplification problem, improves supply chain autonomy, and is suitable for industrial production. The application requirements in the fields of high-end medicines and materials are met.

The invention provides a synthesis method of a high-purity hafnium-zirconium metal complex precursor, and belongs to the technical field of high-dielectric-constant materials for super-large-scale integrated circuits. According to the method, hafnium tetrachloride or zirconium tetrachloride is used as a metal source and sequentially reacts with dialkylamine, n-butyllithium and an alkyl magnesium halide Grignard reagent through a one-pot method in a high-purity inert atmosphere, an intermediate does not need to be separated, and a target precursor is obtained after filtration, washing and rectification. The method is simple and convenient in process operation, mild in reaction condition and low in energy consumption; the raw materials are wide in source and low in price, the product yield reaches 82%-88%, and the metal purity is stabilized to be 6N; when the precursor is used for preparing a hafnium oxide / zirconium thin film through atomic layer deposition (ALD), the thickness of the thin film reaches 14.3 nm under 100 cycles, the non-uniformity is smaller than or equal to 0.90%, the requirement of a gate dielectric layer of a super-large-scale integrated circuit for a high-purity and high-efficiency precursor can be met, and the precursor is suitable for industrial amplification production.

The invention belongs to the technical field of deuterated organic chemical synthesis, and particularly relates to a synthesis method of deuterated 9-phenyl anthraceneboronic acid-D8, which comprises the following steps of: 1, halogenation reaction: reacting 9-phenyl anthracene-D9, bromo-succinimide (NBS) and triethylamine (TEA) in dichloromethane at low temperature to generate an intermediate 9-phenyl-10-bromoanthracene-D8; step 2, carrying out nucleophilic reaction of forming carbon negative by pulling out bromine with strong in a low-temperature environment of-65 DEG C to-70 DEG C, reacting n-butyllithium with the intermediate 9-phenyl-10-bromoanthracene-D8 in 2-methyltetrahydrofuran to generate 9-phenyl anthracene lithium; then triisopropyl borate is added for a boronation reaction, and the 9-phenyl anthracene boric acid-D8 is obtained after hydrochloric acid hydrolysis and purification. The purity of the deuterated 9-phenyl anthracene boric acid-D8 is greater than or equal to 99.8%, the deuteration rate is greater than or equal to 98%, and the deuterated 9-phenyl anthracene boric acid-D8 is suitable for being used as

The invention discloses a solid defoamer suitable for ceramic glazing and a preparation method thereof. The solid defoamer comprises the following formula: 10-30 parts of rhamnose, 0.0001-0.05 parts of a DMC bimetallic catalyst, 5-20 parts of polyoxyethylene, 5-40 parts of polyoxypropylene, 0.1-2.5 parts of a hydrogen capping agent, 5-20 parts of polydimethylsiloxane, 5-20 parts of carborane, 1-5 parts of n-butyllithium, 0.0001-0.009 parts of cis-dichlorodiammineplatinum, 3-8 parts of methyldichlorosilane, 0.0001-0.01 parts of ferric chloride, 0.8-4 parts of ammonium chloride, 10-30 parts of bovine bone ash, 6-20 parts of fumed silica, 0.001-3.5 parts of light calcium carbonate, 0.8-3.0 parts of phenoxyethanol, 0.001-0.2 parts of iodopropynyl n-butylcarbamate, and 20-40 parts of water. The present invention utilizes carborane to enhance ceramic properties while avoiding the problem of residue disposal. The dispersion of silicon dioxide and light calcium carbonate ensures uniform dispersion and stable ceramic components. The use of cattle bone ash as a dispersant ensures uniform dispersion and a moist ceramic surface.

The invention belongs to the technical field of ceramic precursors, and particularly relates to a silicon-boron-carbon-nitrogen ceramic precursor with a main chain containing alkynyl and a preparation method of the silicon-boron-carbon-nitrogen ceramic precursor. Comprising the following steps: (1) dropwise adding an n-butyllithium solution into an ether solvent, stirring, continuously dropwise adding trichloroethylene, and reacting to obtain an alkynyl dilithium salt turbid solution; (2) adding boron trichloride into the alkynyl dilithium salt turbid solution to carry out primary dechlorination polycondensation reaction, and dropwise adding dichlorosilane to carry out secondary dechlorination polycondensation reaction after the reaction is completed; (3) adding hexamethyldisilazane into the system in the step (2) to carry out an end-capping reaction, collecting supernate after the reaction is finished, and distilling at normal pressure to remove the solvent, so as to obtain a silicon-boron-carbon-nitrogen ceramic precursor crude product; and (4) dissolving the silicon-boron-carbon-nitrogen ceramic precursor crude product in an organic solvent, carrying out dialysis treatment, and carrying out atmospheric distillation on the solution in a dialysis membrane to remove the solvent so as to obtain the silicon-boron-carbon-nitrogen ceramic precursor with the main chain containing alkynyl, and the ceramic yield of the silicon-boron-carbon-nitrogen ceramic precursor in the high-temperature ceramization process can reach more than 70%.

The application relates to a solution polymerization styrene-butadiene SSBR rubber and a preparation method thereof, and belongs to the technical field of solution polymerization styrene-butadiene rubber. The preparation raw materials of the solution polymerization styrene-butadiene SSBR rubber include 25-35 parts of styrene, 30-40 parts of butadiene, 75-85 parts of a cyclohexane solution, 0.5-1.5 parts of a polarity regulator, 2-5 parts of an atomization terminator and 0.5-2.5 parts of n-butyllithium. The preparation raw materials of the atomization terminator include 75-85 parts of isopropyl alcohol, 15-20 parts of an antioxidant 1520, 0.5-1.5 parts of cyclohexane, 0.3-0.6 parts of citric acid, 2-4 parts of a plant polyphenol extract and 0.2-0.5 parts of a crosslinking agent. By compounding the antioxidant 1520 and the multi-source purified plant polyphenol extract in the atomization terminator and matching the tannin acid-boric acid composite crosslinking system, a multiple synergistic heat-resistant protection and structure reinforcing mechanism is formed, and the defects of easy oxidative degradation, easy molecular chain rupture and serious performance attenuation of the traditional solution polymerization styrene-butadiene SSBR rubber under a high-temperature environment are effectively improved.

The invention provides a phenyl phosphonic acid bis (o-isocyano-phenol) ester ligand which is prepared by the following steps: in an inert gas atmosphere, mixing a compound benzoxazole with anhydrous tetrahydrofuran, cooling to-95 to-65 DEG C, adding an n-butyllithium solution dissolved in an organic solvent, stirring at-95 to-65 DEG C for 0.5-4 hours, adding diphenylphosphoryl chloride, stirring at room temperature for 8-10 hours, filtering, washing, and drying to obtain the phenyl phosphonic acid bis (o-isocyano-phenol) ester ligand. Carrying out post-treatment on the obtained reaction liquid to obtain a phenyl phosphonic acid bis (o-isocyano phenol) ester ligand; compared with the most common organic dye photosensitizer, the copper-based photosensitizer prepared from the phenyl phosphonic acid bis (o-isocyano-phenol) ester ligand overcomes the defect that the catalytic activity of the organic dye photosensitizer is rapidly reduced under long-term illumination, and in addition, the organic dye photosensitizer is easy to generate an aggregation-induced quenching effect; the photosensitizer disclosed by the invention does not generate an aggregation-induced quenching effect; compared with an iridium complex photosensitizer which is commonly used at present, the cuprous photosensitizer provided by the invention is more environment-friendly.

The invention relates to a preparation method of (bis (trimethylsilyl) amino) tris (pyrrolidinyl) hafnium, which comprises the following steps: (1) reacting bis (trimethylsilyl) sodium amide with hafnium tetrachloride to obtain (bis (trimethylsilyl) amino) hafnium trichloride; (2) reacting tetrahydropyrrole with sodium hydride to obtain sodium pyrrolidinyl; and (3) carrying out a reaction on the (bis (trimethylsilyl) amino) hafnium trichloride obtained in the step (1) and the sodium pyrrolidinyl obtained in the step (2) to obtain the (bis (trimethylsilyl) amino) tris (pyrrolidinyl) hafnium. By optimizing the preparation method of (bis (trimethylsilyl) amino) tri (pyrrolidinyl) hafnium in the prior art, the obtained method is short in synthesis path and simple in synthesis operation, the use of n-butyllithium is avoided, the danger is reduced, the reaction convenience is improved, the raw material cost is low, the product yield and purity are high, and the method is suitable for industrial production. The industrial large-scale production is facilitated.

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 relates to the technical field of argon graded replacement, in particular to an argon graded replacement method for synthesizing n-butyllithium. Comprising the following steps: arranging a gas accommodating cavity between adjacent reaction kettles, and controllably communicating the gas accommodating cavity with a gas outlet of a front-stage reaction kettle and a gas inlet pipeline of a rear-stage reaction kettle through a control valve group; firstly, pretreatment equipment (a branch pipe) of a single kettle is started, argon is introduced, mixed gas in a pipeline blind area is removed, then the argon time sequence and flow of upstream, downstream and midstream gas inlets are controlled, a stable pressure gradient is formed, and the mixed gas in the kettle is directionally pushed to a gas containing cavity; mixed gas in the front-stage gas accommodating cavity is introduced into the rear-stage kettle for repeated replacement and is finally discharged from the tail end; according to the method, blind area purification is enhanced, the replacement efficiency is improved, argon consumption is reduced, inert gas waste is reduced, carbon emission reduction is assisted, and atmospheric pollution prevention and control are assisted.

This invention belongs to the field of polymer materials technology and relates to a method for preparing a self-crosslinkable polysiloxane with adjustable boron content. The invention discloses a method for preparing a self-crosslinkable polysiloxane with adjustable boron content, comprising: S1, filling a reaction flask containing carborane with an inert gas, then adding a reaction solvent and dropwise n-butyllithium to the reaction flask under an ice bath environment, and proceeding with a first reaction after the addition is complete; S2, at -40 to -100°C, adding chlorosilane dropwise to the above-mentioned reaction flask filled with inert gas and containing the reaction product of step S1, and proceeding with a second reaction after the addition is complete; S3, removing the lithium salt to obtain the monomer of the polyborosilicate; S4, mixing the chlorosilane monomer of the polyborosilicate with an amine compound, adding a reaction solvent, and performing a three-stage heating reaction to obtain the polyborosilicate; S5, dissolving the polyborosilicate in a solvent and reacting it with a catalyst at 60 to 300°C for 2 to 12 hours.

The present invention relates to a kind of preparation method of 9 anthracene boronic acid, belong to the field of chemical synthesis technology.The preparation method of 9 anthracene boronic acid that the present invention is provided, using refined anthracene, diboric acid as raw material, under the effect of catalyst, ligand and oxidant, by one-step C H boration reaction prepares 9 anthracene boronic acid.In prior art, the preparation of 9 anthracene boronic acid mainly often first uses refined anthracene as raw material to synthesize 9 bromoanthracene (Path B) through bromination reaction, then using 9 bromoanthracene, n-butyllithium and trimethyl borate etc. as raw material, at 78 DEG C, low temperature lithiation boration reaction prepares 9 anthracene boronic acid (Path A), reaction process is complicated, condition is harsh;And the present invention solves the above problem from the root, directly using cheap refined anthracene, diboric acid as raw material, one-step C H boration reaction obtains product 9 anthracene boronic acid, compared with prior art, reactions steps is short, without intermediate product, also saves the steps such as intermediate product purification, purification, more simple and efficient.

The invention belongs to the technical field of preparation of artemisinin, and discloses a preparation method of artemisinin, which comprises the following steps: reacting diisopropylamine with n-butyllithium in anhydrous THF (tetrahydrofuran) to generate strong base lithium diisopropylamide and obtain a strong base lithium diisopropylamide solution; step 2, then adding a mixed solution of artemisinin and THF into the strong base lithium diisopropylamide solution; the strong base lithium diisopropylamide is used as a strong base to capture specific acidic hydrogen in artemisinin molecules to form an enol salt intermediate; benzene sulfonyl chloride is added to react with hydroxyl of the enol salt intermediate to generate sulfonate; taking a sulfonate group as a good leaving group, carrying out beta-elimination under an alkaline condition to form a double bond, reacting to obtain an artemisinin solution, and purifying the artemisinin solution to obtain a pure product artemisinin; according to the method, benzenesulfonyl chloride and artemisinin which are low in price and easy to obtain are used as main raw materials, the artemisinin is synthesized through a one-pot method, and the method is simple in process, environmentally friendly, high in yield and suitable for industrial production.

The present invention belongs to the field of pharmaceutical synthesis technology and specifically relates to a method for preparing an empagliflozin intermediate compound. The method uses 2-chloro-5-iodobenzyl bromide and (S)-3-(4-bromophenoxy)tetrahydrofuran as starting materials, reacting them under the catalysis of magnesium and 2,2,6,6-tetramethylpiperidinyl oxide to produce the empagliflozin intermediate compound (S)-3-(4-(2-chloro-5-iodophenyl)phenoxy)tetrahydrofuran. This process eliminates the need for n-butyl lithium, has a short synthetic route, is simple to operate, and is more suitable for large-scale industrial production.

The invention provides a preparation method of cyclopentadienyl tris (dimethylamino) hafnium, which comprises the following steps: (1) mixing a hydrocarbon solvent, hafnium tetrachloride and dimethylamine, and adding an alkali metal compound for reaction; and (2) adding cyclopentadiene into the reaction liquid in the step (1), and reacting to obtain the cyclopentadienyl tris (dimethylamino) hafnium, the alkali metal compound is n-butyllithium. The preparation method comprises the following steps: preferentially mixing hafnium tetrachloride and dimethylamine, then dropwise adding n-butyllithium to prepare tetra (dimethylamino) hafnium, and adding cyclopentadiene to obtain the product. According to the method, the synthesis steps of the product are reduced, the reaction time is shortened, and the yield and the purity are improved.

The present invention relates to a method and device system for preparing a dialkylamino metal complex and a triguanidine metal complex. The preparation method provided by the present invention combines the regulation and control of reaction conditions to promote reactions that are favorable for product generation, reduce the occurrence of side reactions, avoid the defect of introducing metal impurities using n-butyl lithium, and avoid the generation of components such as lithium salts that are inconvenient for subsequent separation, thereby facilitating product purification. Moreover, the dialkylamino metal complex and triguanidine metal complex prepared by the present invention meet the purity requirements for precursor materials in integrated circuit manufacturing.

This invention discloses a novel method for preparing and applying quinoline-2-boron ester. A one-pot method is used with a hexane solution of 2-bromoquinoline and n-butyllithium as raw materials, and tetrahydrofuran as solvent. At -70 to -90°C, 2-lithiumquinoline is formed, which is then captured by triisopropyl borate to generate isopropyl-quinoline-2-boron ester lithium salt. Without separation, the formed isopropyl-quinoline-2-boron ester lithium salt is directly reacted with N-phenyldiethanolamine to generate a novel quinoline-2-boron acid N-phenyldiethanolamine ester. The entire reaction process is simple and easy to operate, and the resulting product is easily separated and purified, with a yield of over 80%. The preparation cost is significantly reduced, the experiment has good reproducibility, and it has significant commercial application potential.

The invention discloses a synthesis method of (2S)-N-fluorenylmethoxycarbonyl-3-(1-tert-butyloxycarbonyl-4-piperidyl) propionic acid, and relates to the technical field of synthesis of (2S)-N-fluorenylmethoxycarbonyl-3-(1-tert-butyloxycarbonyl-4-piperidyl) propionic acid, in particular to a synthesis method of (2S)-N-fluorenylmethoxycarbonyl-3-(1-tert-butyloxycarbonyl-4-piperidyl) propionic acid. The invention aims to solve the problem that (2S)-N-fluorenylmethoxycarbonyl-3-(1-tert-butyloxycarbonyl-4-piperidyl) propionic acid is not easy to produce in batches. The method comprises the following steps: S1, N-Boc-4-piperidine methanol and paratoluensulfonyl chloride are subjected to a reaction at room temperature to obtain 1-N-BOC-4-(4-methylbenzenesulfonyloxymethyl) piperidine; the defects of complex process, low safety, high cost and the like caused by the use of platinum oxide for high-pressure catalytic hydrogenation, flammable and explosive n-butyllithium, expensive chiral reagents and the like in the traditional method are avoided, and large-scale production is successfully realized.

The invention discloses a synthesis method of 2-methyl-1H-1, 2, 4-triazole-3 (2H)-ketone, which comprises the following steps: adding a compound 1, namely 1-methyl-1, 2, 4-triazole into an organic solvent I, integrally cooling to-80 DEG C to-50 DEG C under the protection of inert gas, then dropwise adding an n-butyllithium solution, after dropwise adding, keeping the temperature to-80 DEG C to-50 DEG C, stirring and reacting for 0.5-2 hours, and then cooling to room temperature to obtain the 2-methyl-1H-1, 2, 4-triazole-3 (2H)-ketone. The preparation method comprises the following steps: adding a compound 1 into an organic solvent I, dropwise adding a solution obtained by dissolving iodine into an organic solvent II at-80 DEG C to-50 DEG C, after dropwise adding, naturally heating to room temperature, reacting for 8-20 hours, and after the reaction is finished, carrying out first post-treatment to obtain a compound 2, namely 5-iodine-1-methyl-1H-1, 2, 4-triazole; and adding the crude product of the compound 2 into an alkaline aqueous solution, heating to 50-200 DEG C, reacting for 10-20 hours, and performing secondary post-treatment after the reaction to obtain a compound 3, namely 2-methyl-1H-1, 2, 4-triazole-3 (2H)-ketone.