2065results about How to "Few reaction steps" patented technology

The invention discloses a method for preparing a difluoromethoxy bridge type liquid crystal compound, which comprises the following steps: uniformly mixing a compound shown in a formula II and a compound shown in a formula III with alkali under the condition that a catalyst exists for reaction and obtaining a compound shown in a formula I after reaction. The method has the beneficial effects that a reaction substrate is changed into the compound shown in the formula II and a phenylo boric acid derivative shown in the formula III, the reaction steps are reduced, a reaction intermediate is simplified, the total reaction yield is greatly improved, and different group compounds can use the same intermediate formula I. The method is particularly suitable for preparing the difluoromethoxy bridge type liquid crystal compound. Formula II, formula III and formula I are shown in the instruction.

The invention discloses a method for preparing 2,3,3,3-tetrafluoropropene, comprising the following steps: a. in the presence of a fluorinated catalyst, hydrogen fluoride and 1,1,2,3-tetrafluoropropene enter into a first reactor to react; b. in the presence of the fluorinated catalyst, 2-chloro-3,3,3 trifluoropropene, 2-chloro-1,1,1,2-tetrafluoropropane, 1,1,1,2,2-pentafluoropropane and hydrogen fluoride enter into a second reactor to react; c. the product flows obtained in the steps a and b enter into a first distillation tower to be separated; the tower top components are hydrogen chloride and 2,3,3,3-tetrafluoropropene which break away from the system and others are column reactor components; and d. the column reactor components in the step c enter into a second distillation tower to be separated; the column reactor components include 2-chloro-3,3,3 trifluoropropene and 2-chloro-1,1,1,2-tetrafluoropropane which are recycled to the second reactor; and the tower top components, including hydrogen fluoride and 1,1,1,2,2-pentafluoropropane, are recycled to the first reactor or/and the second reactor to be used.

The invention relates to the field of chemical synthesis, in particular to a method for preparing cabazitaxel. Reaction steps are reduced, a protective group is removed in a mild mode, the reaction period is shortened, and the high-purity cabazitaxel is obtained. The whole preparation method has the advantages of a few reaction steps, light pollution and suitability for industrial production.

The invention discloses a method for synthesizing dihydroxyl-terminated polysiloxane. The method synthesizes the target dihydroxyl-terminated polysiloxane compound by using unsaturated epoxy compound, tetramethyldisiloxane, methylaminoethanol and octamethylcyclotetrasiloxane as starting materials and by hydrosilylation, epoxy-opening and equilibrium polymerization. The hexamethyldisilazane or trimethylchlorosilane are not needed as a hydroxyl protector, so the production cost is reduced; and hydroxyl protection and deprotection are avoided in a preparation process, so reaction steps are reduced, the total reaction time for synthesizing the final product is short and the production efficiency is increased.

The invention discloses a method for preparing a compound shown as the formula (I), which is characterized by comprising the following steps of: (1) carrying out hydroxyl protection on a compound shown as the formula (II) by using a first hydroxyl protecting group, and then, reacting with hydride to generate a compound shown as the formula (III); (2) carrying out hydroxyl protection on the compound shown as the formula (III) by using a second hydroxyl protecting group, and then, removing the first hydroxyl protecting group to obtain a compound shown as the formula (IV); (3) enabling the compound shown as the formula (IV) to carry out non-corresponding selective epoxidation reaction to generate a compound shown as the formula (V); (4) reacting the compound shown as the formula (V) with thecompound shown as the formula (VI) in a polar aprotic solvent to obtain a compound shown as the formula (VII); and (5) carrying out condensation, desilylation and oxidization on the compound shown asthe formula (VII) to generate the compound shown as the formula (I). In the general formulas of the compounds in each step, R1 is selected from naphthyl or any substituted naphthyl; R2 is selected from alkyl or benzyl of C1-C4; P is selected from hydroxyl protecting groups, such as 2-methoxyl propyl or p-methoxyl benzyl and the like; P' is a hydroxyl protecting group capable of resisting and removing P, such as benzyl; and X is selected from Cl, Br, I or benzyloxyl.

The invention discloses a synthesis process of chiral pyrrolidine and intermediates. The synthesis process adopts 2, 5-difluorohalobenze or 5-fluoro-3 halogenated pyridine as the raw material substrate, and employs a chiral catalyst to induce chiral reaction so as to reduce a ketone compound into a corresponding chiral alcohol compound, and then carries out substitution reaction to introduce an easily leavable group to an alcoholic hydroxyl group so as to facilitate ring formation reaction (or carry out ring formation reaction directly). The process provided by the invention has the advantagesof significant increase of product yield and reduction of cost, also the reaction temperature is mild, and the process is easy to control and industrialize.

The invention relates to the technical field of drug synthesis, and particularly relates to a synthetic method of kyprolis. The synthetic method comprises the following steps: carrying out condensation reaction on morpholine-4-base acetic acid, L-homophenylalanine ester and salt, and then carrying out decarboxylation protection to generate a compound V; carrying out the condensation reaction on the decarboxylation, the salt and N-Boc-L-leucine, and then carrying out deamination protection to generate a compound VI; carrying out the condensation reaction on the compound V and the compound VI, and then carrying out decarboxylation protection to generate a compound VII; carrying out the condensation reaction on the compound VII and a compound VIII to obtain the kyprolis. The method disclosed by the invention can be used for enhancing the reaction yield by adopting a converging synthetic method; the used reagent is easy, convenient, easy to obtain and less in pollution. The process disclosed by the invention only relates to the condensation and deprotection between amino acids and is simple and controllable in reaction and suitable for industrial production.

The invention belongs to the technical field of biomass conversion utilization, and concretely relates to a method for preparing cyclopentanone by taking biomass resource as a raw material. The method comprises taking furfural coming from biomass as the raw material, taking a hydrogen-containing gas as a reducing agent, and in the presence of a metal supported type catalyst, performing hydrogenation rearrangement reaction in a high-pressure reaction kettle or a fixed bed reactor, so as to obtain cyclopentanone in one step, wherein the carrier of the metal supported type catalyst is selected from Nb2O5, H-ZSM-5 molecular sieve, HY molecular sieve, Fe2O3, ZrO2, Al2O3, SiO2, CeO2, MgO, active carbon, and TiO2 in various crystal forms, the active composition is selected from Au, Pt, Ru, Rh, Pd, Ir, Ni and Cu, and the active composition load capacity is 0.1-5% of the catalyst. The method is mild in reaction technological conditions, and cheap and easily-available in raw materials, is capable of realizing quantitative conversion of furfural to cyclopentanone, and belongs to an environment-friendly green chemical technology.

The invention provides a high impact high gloss bimodal polystyrene material and preparation method thereof, comprising the following steps: (a) the solution of polybutadiene rubber component mixed with polystyrene monomers is provided; wherein, the polybutadiene rubber component is selected from high cis-polybutadiene and/or low cis-polybutadiene, the cis-content of high cis-polybutadiene is not less than 94% by mole and the cis-content of low cis-polybutadiene is between 33% to 40% by mole ; (b) the solution obtained from the step (a) is used to perform prepolymerization reaction of styrene monomers to obtain a prepolymerization solution system which does not generate phase transition; (c) the prepolymerization solution system obtained from the step (b) is used to perform further prepolymerization reaction of styrene monomers in shearing force field until the system generates phase transition to obtain rubbery state material of which the particle size presents bimodal distribution; (d) the conversion rate of styrene monomers in the material obtained from the step (c) is further increased to obtain the high impact high gloss bimodal polystyrene material. The invention also provides a preparation method of the high impact high gloss bimodal polystyrene material.

The invention discloses a semi-synthesis method for high-purity and high-stability gastrodin. The semi-synthesis method comprises the following steps: carrying out a reduction reaction by taking tetraacethyl as a raw material; concentrating and adding a suitable amount of water into concentrated liquid; filtering and drying to obtain acethyl gastrodin; recycling a filtering solution which is used as a mother solution a; adding an alcohol solvent into the acethyl gastrodin to carry out a reflowing reaction, and concentrating; repeatedly reflowing and concentrating to obtain a concentrated solution; adding a non-polar solvent and filtering; drying solids to obtain a gastrodin rough product; recycling a filtering solution which is used as a mother solution b; adding alcohol and/or an ester solvent into the rough product of gastrodin; heating and completely dissolving; filtering and separating out crystals to obtain a refined product of gastrodin; recycling a filtering solution which is used as a mother solution c; mixing the mother solution b and the mother solution c; filtering and drying to obtain the rough product of gastrodin; and refining to obtain the refined product of gastrodin. The acethyl gastrodin prepared by the semi-synthesis method disclosed by the invention is stable, can be directly used as a crude drug, and can also be used as an intermediate to synthesize the high-purity gastrodin; the semi-synthesis method for the high-purity and high-stability gastrodin is very good for meeting the clinical demands on gastrodin and acethyl gastrodin.

Disclosed is a Sofalcone preparation method which mainly comprises, (1) subjecting p-hydroxybenzaldehyde and 2,4-ihydroxyacetophenone to condensation reaction under alkaline condition, obtaining 2,4,4-Trihydro-xychalcone, (2) subjecting 2,4,4-trihydro-xychalcone and 1-bromo-3-methyl-2-butene to condensation reaction, obtaining 2-hydroxyl-4,4-bis (3-methyl-2-butenyloxy) chalcone, (3) subjecting the 2-hydroxyl-4,4-bis (3-methyl-2-butenyloxy) chalcone and ethyl bromoacetate to condensation under the action of potasium carbonate, thus obtaining sofalcone. The mol ratio of p-hydroxybenzaldehyde, 2.4-dihydroxyacetophenone, 1-bromo-3-methyl-2-butene, and ethyl bromoacetate can be 1 : (0.90-1.50) : (1.60-2.55) : (0.60-1.25).

The invention relates to the red beam luminescent dye which the receptor group is the 1, 3-indandione and the derivant 4H-pyrones. So the quenching effect of the new dyestuff has decreased efficiently and it has the saturated colour-purity. It can keep high efficient and the brightness in the high doping content. It is used for the organic photoconductor, the organic nonlinear optical material and the luminescent material of the electroluminescent cell. The emission band spectrum is in the red region of the visible spectrum and it has the high fluorescence quantum efficiency.

The invention relates to a method for preparing compound palbociclib (shown as the formula I). A compound D (shown as the formula II) serves as a raw material, and a compound E (shown as the formula III) is obtained through a rearrangement reaction of alkenyl ether; then the compound E is subjected to t-butyloxycarboryl protection group removal under the acidic condition, and target product palbociclib is obtained; an R group in a compound D is selected from any one of a C1-C6 alkyl group, a C1-C6 halogenate alkyl group, C1-C6 hydroxyalkyl and a C1-C6 naphthenic base. The process procedure and operation steps are easy and convenient, prepared palbociclib is high in purity, and good popularization prospects are achieved.

The invention provides a preparation method of erlotinib hydrochloride. The method comprises the following steps: taking 6,7-dimethoxy-3,4-dihydro-quinazoline as an initial raw material, chlorinating directly, then reacting with 3-aminophenylacetylene, afterwards removing methyl on the positions of 6 and 7 and finally introducing a methoxyethyl side chain to generate the erlotinib hydrochloride. The invention has the technological lines of mild reaction condition, no need of high temperature, deep cooling, energy saving and environment friendliness; the whole line has better yield and quality; and the reaction steps are little, the reaction is stable and controllable, the postprocessing is very simple and convenient, and the industrialized production is easy.

The invention discloses a preparation method of low-cost ZSM-5 type zeolite molecular sieve, and application of the low-cost ZSM-5 type zeolite molecular sieve, belonging to the field of a molecular sieve preparation technology. The method comprises the steps of a. drying pulverized fuel ash raw powder to constant weight, mixing HCl solution with the dried pulverized fuel ash, stirring, centrifuging, washing and drying for later use; b. grinding the pulverized fuel ash treated by the step a, mixing the ground pulverized fuel ash with NaOH for melting, cooling, grinding and screening by a molecular sieve; feeding the ground melt into deionized water, mixing, stirring under the condition of water bath, and carrying out centrifugal separation to obtain liquid supernatant; c. taking the liquid supernatant obtained in the step b, taking tetrapropylammonium hydroxide as a template agent and NH4F as a mineralizer, mixing and carrying out crystallization reaction; after that, taking out the product, quenching to the room temperature, washing, drying and roasting to obtain the zeolite molecular sieve. According to the method, the pulverized fuel ash discharged by a thermal power plant is fully utilized as a silicon-alumininm source and is used for replacing pure chemical reagents Si and Al for synthesizing the molecular sieve, so that the synthesis cost of the molecular sieve is lowered, and the utilization value is high.

This invention is attributed to the field of organic chemistry and specifically relates to the method to synthesize drug intermediates (R)-2-amino-1-((R)-6-fluoro-3, 4-dihydrochromeno) ethanol and (R)-2-amino-1-((S)-6-fluoro-3, 4-dihydrochromeno) ethanol. The method is that, drug intermediates (2R)-2-[(1R)-4, 4-dimethyl-3, 5-dioxocyclopentyl]-6-fluoro-4-chromanone and (2S)-2-[(1R)-4, 4-dimethyl-3, 5-dioxocyclopentyl]-6-fluoro-4-chromanone are adopted as raw materials and reduced by Clemmensens method with the products reacting with p-toluenesulfonyl chloride in pyridine. The consequent products are dissolved in solvent and dry ammonia is introduced for heating reflux. The total yield can be as much as 32%.

The invention discloses a preparing method of bicyclohexane monomer LCD in the monomer LCD preparing technical domain, which utilizes Grignard reaction to prepare the product with structural formula as graph I and synthetic feature route as graph II, wherein R1 and R2 is C2-C10; R3 is C1-C9 straight-chain alkyl; X is Cl or Br or I; A is C2H4 or cyclohexane; n is 0 or 1.

The invention discloses a process of preparing of an over-expenditure structure chitose or an over-expenditure ethylene alcohol chitose, which comprises the following steps: degrading the chitose or the ethylene alcohol chitose with nitrous acid or nitrite; getting fractionally more narrow molecular weight distribution high molecular chain a end-groupof which is aldehyde group chitose or ethylene alcohol chitose with method of precipitation or volumetric exclusive chromatography; getting the Schiff's base dissolving in the weakly-acidic or neutral solution; getting the over-expenditure structure chitose or the over-expenditure ethylene alcohol chitose by deacidizing SCHIFF'S base( when R is H in the structural formula, the structure is the over-expenditure structure chitose; when R is CH2CH2OH, the structure is the over-expenditure ethylene alcohol chitose; wherein RI is the same structure branched chain to the broken line part in the above structural formula; the molecular weight range of the over-expenditure structure chitose or the over-expenditure ethylene alcohol chitose is >= 5000Da).

The invention discloses a synthetic method of 4-(2,2-difluoro-1,3-benzodioxole-4-yl)pyrrole-3-nitrile. The method comprises the following steps of: preparing an intermediate 2,2-difluorobenz-1,3-dioxole through reacting catechol with dibromodifluoromethane, and preparing an intermediate 2-cyano-3-(2,2-difluorobenz-1,3-dioxole-4-yl)-2-acrylate. The fludioxonil prepared by the synthetic method provided by the invention has the purity of more than 99.0% and the total yield of more than 45.0%; the synthetic method has the advantages of cheap and easily available raw materials, simple process, high product yield in each step, good purity, low production cost, applicability to batch industrial production and the like.