17 results about "Dicarbonate" patented technology

The invention provides a method for preparing 2, 6-diamino-3, 5-dinitropyridine, which comprises the following steps: (1) reacting 2, 6-diaminopyridine with an amino protection reagent to obtain an intermediate A; (2) in the presence of a dehydrating agent, carrying out double nitration reaction on the intermediate A and a nitration reagent to generate an intermediate B; (3) 2, 6-diamino-3, 5-dinitropyridine is obtained after the intermediate B is subjected to deprotection, and an amino protection reagent is selected from one or more of acetic anhydride, trifluoroacetic anhydride, di-tert-butyl dicarbonate, benzyl chloroformate and concentrated sulfuric acid; wherein the molar ratio of the amino protection reagent to the 2, 6-diaminopyridine is (2: 1)-(30: 1) by mole; and preferably, the ratio is 2: 1-12: 1.

The utility model provides a kind of di-tert-butyl dicarbonate production device, it is related to chemical production technical field, including base, the base includes slab, fixed hole is opened in the slab, fixed sleeve is fixed on the slab top surface, fixed hole is used to fix slab.The utility model will drive connecting plate to rotate from driving pulley rotation, first gear bar rotates around fixed shaft axis center, and will also autorotate under the action of fixed gear, autorotating first gear bar will drive second gear bar and support shell to rotate, in the above process, connecting plate will also drive support shell to rotate around fixed shaft axis center, further make support shell and barrel body autorotate while revolving, realize the mixing of material, the device can save stirring paddle, avoid the cleaning problem brought by paddle structure, barrel body is movably arranged in support shell, convenient to take out and clean, reduce material residue, simplify cleaning process.

The invention belongs to the technical field of ion detection, and particularly relates to a preparation method of a ratio type fluorescent probe for detecting collected ions, which comprises the following steps: dissolving ethylenediamine and di-tert-butyl dicarbonate in perchloroform to obtain a product 1; dissolving the product 1 in absolute ethyl alcohol, and adding 4-Australio-1, 8-dianhydride to obtain a product 2; dissolving the product 2 in thousand dimethyl sulfoxide, and adding N-isothiazolyl phthaloyl to obtain a product 3; dissolving the product 3 in dichloromethane, and adding phenyl thiochloroformate to obtain the fluorescent probe NAP. The preparation method comprises the following steps: dissolving a fluorescent probe NAP in DMSO to prepare a mother liquor A, and dissolving methoxy chitosan CS-MeO in water to prepare a mother liquor B; and mixing the mother liquor A and the mother liquor B to prepare a Nano-NAP solution. The ratiometric fluorescent probe is used for detecting collected ions, has the advantages of high selectivity, small interference, low detection limit, good pH stability and the like, is high in use value, and has a wide application prospect.

The invention discloses a preparation method of an axially chiral biaryl aminophenol compound, which mainly comprises the following steps: adding biaryl amino diphenol, di-tert-butyl dicarbonate ester and a chiral isothiourea catalyst into an organic solvent, cooling to-10 to-30 DEG C for reaction, and after the reaction is completed, separating and purifying to obtain the axially chiral biaryl aminophenol compound. And performing post-treatment to obtain the axially chiral biaryl aminophenol compound. The preparation method can be carried out under mild conditions, is good in stereoselectivity, convenient to operate and simple in post-treatment, and avoids the use of a heavy metal catalyst which may remain in a product; according to the present invention, the reaction raw materials are cheap and easily available, the compatibility of the substrate functional group is good, the amplification treatment can be conveniently performed, the practicability is strong, the diversified axially chiral biaryl aminophenol compound can be designed and synthesized according to the actual requirement, the operation is convenient, and the applicability of the method is widened.

The invention discloses a preparation method of ramelteon. The preparation method comprises the following steps: 1, reacting tetrahydrofuran, sodium hydroxide and diethyl cyanomethylphosphonate to prepare a ylide solution, and dropwise adding the ylide solution into a solution of an initial raw material 1 to prepare an intermediate 1; 2, reducing the intermediate 1 through sodium borohydride under the action of nickel chloride and di-tert-butyl dicarbonate to obtain an intermediate 2; 3, performing hydrochloric acid deprotection on the intermediate 2 in a methanol solution to obtain an intermediate 3; 4, preparing an intermediate 4 through chiral resolution and recrystallization; 4, the intermediate 4 is subjected to propionylation under the alkaline condition, and ramelteon is obtained. According to the method, the intermediate 3 is resolved by using the organic acid which is low in price and easy to obtain in the market. The resolution process is simple, convenient and safe to operate and suitable for industrial production, the prepared ramelteon is high in yield and high in optical purity, and the market competitiveness of the ramelteon is enhanced.

The present invention belongs to the technical field of organic peroxides, and particularly relates to a preparation method of tert-amyl peroxy (2-ethylhexyl) carbonate. The preparation method comprises the following steps: (1) carrying out a temperature-controlled reaction on a crude product of tert-amyl hydroperoxide and a salifying agent under the action of a phase transfer agent to obtain an intermediate; (2) compounding a phase transfer catalyst system, blending the phase transfer catalyst system with 2-ethylhexyl chloroformate, and adding the blend and the intermediate into a reaction kettle in a co-current manner to carry out a substitution reaction. After the substitution reaction is completed, standing and collecting the upper organic phase to obtain a crude TAEC product; (3) adding a detergent to the crude TAEC product, stirring, standing, collecting the upper oil phase, and washing with water until the oil phase is neutral to obtain TAEC. By compounding the phase transfer catalyst system, the present invention solves the problems of many by-products of dicarbonates, low yield of TAEC and difficult catalyst recovery existing in the current TAEC synthesis method.

The invention discloses a preparation method of famotidine, and relates to the technical field of medicine preparation. According to the method, a famotidine crude product is adopted as a raw material, recrystallization is performed for three times in stages, a recrystallization A solution comprising 10-15% of N, N-dimethylformamide, 5-12% of dimethyl sulfoxide, 1-3% of succinic acid and the balance of purified water and a recrystallization B solution comprising 20-25% of linolenic acid, 8-15% of N, N-dimethylformamide, 2-5% of citric acid, 0.5-1% of di-tert-butyl dicarbonate and the balance of purified water are selected, and the famotidine crude product is obtained through crystallization. Comprising a recrystallization solution C containing 15-30% of methanol, 5-10% of p-ethyl propiophenone, 1-5% of paraformaldehyde and the balance of purified water, the finally obtained famotidine finished product is high in purity and high in yield, the content of N-nitrosodimethylamine is 0, and the famotidine finished product is suitable for large-scale production and has very high economic value.

The invention provides a latent amine curing agent as well as a preparation method and application thereof. The curing agent is a mixture containing a compound with a structure I and a compound with a structure II, the structure of the compound with the structure I is shown in the specification, and the structure of the compound with the structure II is shown in the specification. The preparation method comprises the following steps: S1, carrying out primary amine substitution reaction on diamine and Boc anhydride (di-tert-butyl dicarbonate) to generate a secondary amine compound intermediate; and S2, carrying out secondary amine reactive hydrogen substitution reaction on the secondary amine compound intermediate and anhydride containing a fluoroacetic acid structure to obtain a mixture containing a structure I compound and a structure II compound. The latent amine curing agent not only has an excellent storage period and can be stably stored for more than three months after being matched with epoxy resin at room temperature, but also endows a cured product with excellent toughness and solvent resistance due to introduction of a carbamate structure, and has a good application value in the fields of epoxy SMC (Sheet Molding Compound), prepreg and the like.

The invention relates to the technical field of organic synthesis, in particular to a preparation method of difluropyrazole acid, which comprises the following steps: reacting hydrazine hydrate serving as a raw material with di-tert-butyl dicarbonate to generate tert-butyloxycarboryl hydrazine, reacting the tert-butyloxycarboryl hydrazine with a compound obtained by reacting unsaturated ester with 2, 2-difluoroacetyl halide, and removing Boc protecting groups from the obtained product to obtain the difluropyrazole acid. And then carrying out an N-methylation reaction with an N-methylation reagent to obtain the difluopyrazole acid. The yield and purity of the difluopyrazole acid are improved by introducing a protecting group and adjusting a reaction route, and the preparation method has the advantages of low cost, low toxicity, high safety, mild reaction conditions and suitability for industrial production by replacing a highly toxic product methylhydrazine with the cheap hydrazine hydrate.

This invention discloses an imidazoline-type surfactant, its preparation method, and its application, relating to the field of surfactant technology. A method for preparing an imidazoline-type surfactant includes the following steps: (1) adding hydroxyethyl ethylenediamine, di-tert-butyl dicarbonate, an organic base, and a solvent to a reaction vessel for reaction, followed by nitrogen purging and vacuum distillation; (2) adding an alkaline catalyst to the reaction vessel and introducing ethylene oxide, followed by vacuum distillation to obtain precursor A; (3) adding trifluoroacetic acid to precursor A for reaction, followed by vacuum distillation and adding an alkaline salt solution to adjust the pH of the system, adding fatty acids and an acidic catalyst to the reaction vessel, cooling and filtering after the reaction, thus obtaining the imidazoline-type surfactant. The method described in this invention can greatly reduce various side reactions caused by the direct alkyl hydroxyethyl imidazoline ethoxylation, thereby ensuring that the product retains its anti-corrosion properties while improving its water solubility.

The invention discloses a method for preparing (2-amino-1-cyanocyclopentyl) tert-butyl carbamate. The preparation method of the present invention comprises the following steps: (1) using compound 1 as a starting material, dissolving compound 1 in solvent I, adding trimethylsilyl cyanide and ammonia methanol, and reacting under the action of catalyst I to obtain compound 2; (2) dissolving compound 2 in solvent II, adding di-tert-butyl dicarbonate to undergo an acylation reaction, and obtaining compound 3; (3) dissolving compound 3 in solvent III, adding catalyst II to undergo a hydrogenation reduction reaction under the condition of passing hydrogen, and obtaining the (2-amino-1-cyanocyclopentyl) tert-butyl carbamate. The preparation method of the present invention has easy-to-obtain raw materials, simple operation, high yield, and can obtain a single-configuration target compound.

This invention relates to the field of chemical synthesis, and more particularly to a process for producing allyl diethylene glycol dicarbonate, comprising the following steps: using allyl alcohol and dimethyl carbonate as raw materials, a transesterification reaction is carried out under the action of a core-shell catalyst to produce dipropylene carbonate; after solid-liquid separation and vacuum distillation to recover methanol and dimethyl carbonate, a second transesterification reaction is carried out with diethylene glycol under the same catalyst to produce allyl diethylene glycol dicarbonate; finally, high-purity product is obtained by multi-stage vacuum distillation purification. The core-shell catalyst uses MCM-41 molecular sieve as a support, with an amino-modified and zirconium-ion-coordinated core, encapsulated by an interface layer and a phenyl-modified silica shell, exhibiting high activity, high selectivity, and excellent structural stability. This process is mild, the catalyst is recyclable, and the product yield is high with excellent purity, making it suitable for industrial production.

The invention relates to a preparation method of methyl trifluoroethyl carbonate. The preparation method comprises the following steps: (1) carrying out a reaction on di-tert-butyl dicarbonate and trifluoroethanol to obtain an intermediate product; (2) adding dimethyl carbonate into the reaction system in the step (1), and reacting to obtain methyl trifluoroethyl carbonate; the reaction in the step (1) is carried out in the presence of a catalyst. The preparation method has the advantages of few reaction steps and high selectivity and yield. Compared with the existing synthesis method, the synthesis raw material is di-tert-butyl dicarbonate, high-toxicity raw materials such as methyl chloroformate are avoided, and the method is green and environment-friendly. And methanol which can generate ternary azeotropy with the product FEC and the dimethyl carbonate during rectification is not generated in a reaction system, so that the product purity is improved. In addition, the reaction product carbon dioxide in the step (2) escapes, the reaction is promoted to proceed forwards, and the reaction yield is increased.

The application belongs to the technical field of ion detection, and particularly relates to a preparation method of a ratio type fluorescent probe for detecting ions, which comprises the following steps: dissolving ethylenediamine and di-tert-butyl dicarbonate in chloroform to obtain product 1; dissolving the product 1 in anhydrous ethanol, adding 4-nitro-1,8-naphthalic anhydride to obtain product 2; dissolving the product 2 in dimethylformamide, and adding N-phthaloylglycine to obtain product 3; dissolving the product 3 in dichloromethane, and adding phenylthiochloroformate to obtain a fluorescent probe NAP; dissolving the fluorescent probe NAP in DMSO to prepare mother liquor A, dissolving methoxyl chitosan CS-MeO in water to prepare mother liquor B; and mixing the mother liquor A and the mother liquor B to prepare a Nano-NAP solution. The ratio fluorescent probe is used for detecting ions, and has the advantages of high selectivity, small interference, low detection limit, good pH stability and the like, and has high use value and wide application prospect.

The application discloses a boron-nitrogen doped polycyclic aromatic compound and a synthesis method thereof, and relates to the technical field of organic synthesis. The application takes o-bromonitrobenzene as raw material, and first carries out a Bartoli reaction with vinyl magnesium bromide to synthesize 7-bromoindole; then carries out twice coupling reactions under the action of a metal catalyst to form a dimer of indole; carries out a reaction of the dimer of indole with di-tert-butyl dicarbonate to obtain a single Boc dimer of indole; carries out a borohydration reaction on the single Boc dimer of indole to obtain a boron-containing intermediate; and finally carries out a reaction with a Grignard reagent to obtain the boron-nitrogen doped polycyclic aromatic compound. The synthesis method has the characteristics of a relatively short reaction path, simple operation method and mild reaction conditions. Meanwhile, the compound synthesized by the application is sensitive to fluoride ions and has a high fluorescence quantum yield, and can be applied to the fields of fluoride ion sensors and organic photoelectric materials, and has a wide application prospect.

The invention belongs to the technical field of flame retardants, and particularly relates to a novel high-temperature self-cracking curing agent and a preparation method thereof, and application of the curing agent in preparation of active flame-retardant epoxy resin. The high-temperature self-cracking curing agent is prepared by taking organic aliphatic diamine, organic aliphatic amine, di-tert-butyl dicarbonate ester, cyanuric chloride and triethylamine as raw materials through a three-step reaction. The curing agent has two triazine structures and a polyamine structure, the triazine structure has double functions, on one hand, the triazine structure has a flame retardant function and can be decomposed at high temperature to release inert gas to dilute oxygen concentration to suffocate flame, and on the other hand, the curing agent is self-cracked before the self-combustion of an epoxy resin material, so that the self-combustion performance of the epoxy resin material is improved. The three-dimensional network structure of the polymer is decomposed, so that the combusted part of the polymer is separated from a matrix under the action of inert gas, and active flame retardance and fire prevention are realized. Limit oxygen index (LOI) and vertical combustion UL-94 experiment results show that the curing agent can endow an epoxy resin material with good flame retardant property, and the LOI value can be up to 33.8% and passes the UL-94V-0 level; a cone calorimeter test shows that the curing agent can significantly reduce the total smoke generation amount of the epoxy resin material. In addition, the curing agent belongs to an environment-friendly halogen-free flame retardant, the preparation process is simple, the yield is 90% or above, and industrial production is easy.

The invention relates to the technical field of medical materials, in particular to a borate disubstituted tyrosine derivative and a synthesis method and application thereof. The structural formula of the borate disubstituted tyrosine derivative is as shown in formula (I). The invention also provides a synthesis method of the borate disubstituted tyrosine derivative, which comprises the following steps: adding tyrosine into a solvent, cooling, adding di-tert-butyl dicarbonate, reacting to obtain a compound, dissolving the compound in dimethylformamide, adding N-halogenated succinimide, reacting to obtain a halogenated compound, dissolving the halogenated compound in the solvent, adding dimethyl sulfate and anhydrous potassium carbonate, reacting, filtering, washing and drying to obtain the borate disubstituted tyrosine derivative. And dissolving the intermediate halogenated compound in isopropyl acetate, adding potassium acetate, bis (pinacolato) diboron and a catalyst, reacting to obtain a compound, dissolving the compound in acid, and reacting to obtain the borate disubstituted tyrosine derivative. The invention also provides application of the borate disubstituted tyrosine derivative. The invention provides a novel boric acid-based tyrosine derivative, and solves the problem of low boron loading amount of the existing boron medicine. (I).