132 results about "Propionic anhydride" patented technology

The invention discloses a method for preparing Parecoxib. The method for preparing the Parecoxib comprises the following steps of: performing sulfonation reaction on 1,2-diphenyl butanone serving as a raw material to obtain 1-phenyl-2-(4-sulfo phenyl)butanone; in the presence of alkali, performing condensation on the 1-phenyl-2-(4-sulfo phenyl)butanone and acetylchloride to prepare 1-phenyl-2-(4-sulfo phenyl)-2-acetyl butanone; performing cyclization on the 1-phenyl-2-(4-sulfo phenyl)-2-acetyl butanone and hydroxylamine hydrochloride to obtain 4-(5-methyl-3-phenyl-4-isoxazole)benzenesulfonic acid; performing chlorination and ammonolysis reaction to prepare Bextra; and reacting the Bextra with propionic anhydride to synthesize the Parecoxib. In the method, the raw materials are readily available and reaction conditions are not rigorous. The method is easy and convenient to operate and has certain industrialized value.

A disinfectant with hydrogen peroxide bactericidal activity is composed of A, B, C and D component. If the solute is metered by 100%, its weight account proportion of mixed solution A:B:C:D=5-100:1-50:1-100:1-1000 obtained through hydrogen cation resin exchanged and filtered, wherein A is hydrogen peroxide; B is form one or more of glutaric anhydride, adipic anhydride, succinic anhydride, acetic anhydride, propionic anhydride, benzoic anhydride and phthalic anhydride; C is from one or more of sulfuric acid, phosphoric acid, salicylic acid, tartaric acid, citric acid, dipicolinic acid, sorbic acid, acetic acid, glutaric acid, oxalic acid, succinic acid, acetic acid, propionic acid, benzoic acid, and phthalic acid; D is from one or more of ethanol, ethylene glycol, isopropanol, glycerol, and polyvinyl alcohol. It is a good stability, strong bactericidal, fungicidal spectrum-efficient disinfectant.

The invention discloses a rice starch based biodegradable packaging film and a preparation method thereof. The rice starch based biodegradable packaging film is prepared from the following raw materials in percentage by weight: 15-55% of rice starch, 0.01-0.1% of alpha-amylase, 5-15% of chitosan, 2-10% of sodium benzoate, 2-10% of potassium sorbate, 2-10% of propionic anhydride, 10-55% of polyvinyl alcohol, 0.01-0.05% of a crosslinking agent, and 0.8-10% of a plasticizer and 15-30% of distilled water. The invention also discloses a preparation method of the rice starch based biodegradable packaging film. The rice starch based biodegradable packaging film disclosed by the invention is strong in antibacterial activity, good in water resistance and acid and alkali resistance, and high in strength, and after being disposed, can be decomposed into carbon dioxide and water by microorganisms in environments.

The invention relates to a preparation method of cellulose acetate propionate, belonging to technical field of cellulose modification. The preparation method of cellulose acetate propionate comprises the following steps of: taking cellulose as a raw material, activating by a mixed solution of acetic anhydride and propionic anhydride, adding acetic acid and propionic acid solvents and a solid super acidic catalyst for esterification, after esterification, filtering to remove the catalyst, adding waste acid water for hydrolyzing, settling out by waste acid water, and finally obtaining the cellulose acetate propionate by steps of filtering, washing, drying and the like. The production process is simple to operate, the solid super acidic catalyst substitutes the concentrated sulfuric acid catalyst and can be cyclically used for many times, thus alleviating the problem of serious corrosion of the original process equipment. The waste acid water generated in the reaction process only contains acetic acid and propionic acid without sulfuric acid and can be fully recovered and cyclically used, thus decreasing the tension in environmental protection, realizing zero discharge and greatly reducing the production cost. The cellulose acetate propionate prepared by the method has fine toughness, heat stability and compatibility, thus being extensively used.

A parecoxib preparation method comprises the following steps: reacting diacetophenone oxime with ethyl acetate in a lithium diisopropylamide / tetrahydrofuran system to generate 4,5-dihydro-5-methyl-5-hydroxy-3,4-dibenzylisoxzzole; reacting 4,5-dihydro-5-methyl-5-hydroxy-3,4-dibenzylisoxzzole with halogenated sulfonic acid, and ammonolyzing to obtain valdecoxib; and reacting valdecoxib with propionic anhydride to obtain parecoxib. Compared with the prior art, the preparation method disclosed in the invention has the advantages of low initial raw material cost, simple and feasible technological process, low equipment requirement, and suitableness for the industrialized large-scale production.

As during the process of preparing asarin from 1, 2, 4-trimethoxybenzene, the raw materials of propionic anhydride, propionyl chloride, anhydrous aluminum chloride, anhydrous zinc chloride, dichloromethane, sodium borohydride, sodium propionate and the like with low prices are used, the production cost is lowered greatly. At the same time, the post treatment of the invention is convenient; products of each step are all solids which are convenient for detecting; the reaction yield of each step is high; and the production process generates few three wastes. In conclusion, in the invention, the 1, 2, 4-trimethoxybenzene which is obtained easily in China is used as a raw material to prepare the asarin by the reactions such as acidylation and the like; the invention has low cost, safe and simple operation, high reaction yield and less environmental pollution; and compared with the existing reported method, the invention is fit for the industrialized production better.

The invention discloses a preparation method of pramipexole dihydrochloride. The preparation method comprises the following steps: 1) in an organic solvent, by taking 2,6-diamido-4,5,6,7-tetrahydrobenzothiazole as a raw material, adding a resolving agent, heating for reflux and carrying out cooling, suction filtration and alkalization to prepare (-)-(6s)-2,6-diamido-4,5,6,7-tetrahydrobenzothiazole; 2) in an ethyl alcohol solution, carrying out reaction on (-)-(6s)-2,6-diamido-4,5,6,7-tetrahydrobenzothiazole and propionic anhydride and heating for reflux to prepare (-)-(6s)-2-amino-6-propionylamino-4,5,6,7-tetrahydrobenzothiazole; 3) carrying out reduction reaction on (-)-(6s)-2-amino-6-propionylamino-4,5,6,7-tetrahydrobenzothiazole in a methylbenzene solution by red aluminum, heating for reflux and carrying out stirring and crystallization to prepare pramipexole; 4) dissolving the pramipexole in an isopropanol solution, reacting with hydrochloric acid after stirring and crystallization and carrying out decompression and drying to obtain pramipexole dihydrochloride. The preparation method is low in requirements for reaction equipment; the prepared pramipexole dihydrochloride is high in content, high in purity, high in solubility, high in output and less in impurity.

The invention relates to a preparation method of cellulose acetate propionate microspheres by an ionic liquid as a solvent. The preparation method utilizes a homogeneous esterification method to realize cellulose acetate propionate synthesis and realizes cellulose acetate propionate regeneration thereby producing the cellulose acetate propionate microspheres. The preparation method comprises the following steps of dissolving cellulose in an ionic liquid to obtain a cellulose solution, carrying out a process of a reaction of a propionic anhydride-acetic anhydride mixed solution and the cellulose solution, dispersing the above mixed solution into an oil phase, coagulating the cellulose solution by reversed phase suspension and programmed freezing to obtain cellulose solution drops, adding a curing agent into the cellulose solution drops for curing the cellulose solution drops so that cellulose microspheres are formed, after the reaction, carrying out solid-liquid phase centrifugation to obtain the cellulose acetate propionate microspheres and recovering the ionic liquid. The cellulose acetate propionate microspheres have regular spherical shapes, an acetyl substitution degree of cellulose acetate propionate is in a range of 0.02-0.5 and a propionyl substitution degree is in a range of 0.03-0.4, good mechanical properties, good thermostability and acid and alkali resistance are obtained, and the cellulose acetate propionate microspheres can be used for separation purification of biomacromolecule proteins and can also be used as a carrier of an enzyme or other biomaterials.

The present invention relates to continuous propionic aldehyde oxidizing process for producing propionic acid and its reaction tower. The production process includes the following steps: mixing propionic aldehyde with catalyst, feeding the mixture of propionic aldehyde and catalyst and air or oxygen to the bottom of reaction tower, and reaction at 80-100 deg.c to obtain coarse propionic acid overflowing in the upper part of the reaction tower. The production process has the features of short technological process, high catalyst activity, low reaction pressure and temperature, short reaction time and high selectivity, and is suitable for industrial production. The present invention has propionic aldehyde converting rate up to 95 %, propionic acid selectivity up to 97 % and propionic acid yield up to 92 %.

The syntyesis of (-)-2-amino-6-propionamido tetrahydro benzothiazole features the adopting common chemical material 4-amin cyclohexanol as initial material, and the six-step process including N-acetylating reaction for protecting amino radical, oxidation with Jones reagent to prepare 4-acetamido cyclohexanone, thiazole annelation, HBr hydrolysis, tartaric acid chiral compound resolution, propionic anhydride acylation. The present invention has mild reaction condition, easy control, simple production process, low production cost, high reaction yield and easy industrial application.

A hardmask composition for forming a resist underlayer film, a process for producing a semiconductor integrated circuit device, and a semiconductor integrated circuit device, the hardmask composition including an organosilane polymer, and a stabilizer, the stabilizer including one of acetic anhydride, methyl acetoacetate, propionic anhydride, ethyl-2-ethylacetoacetate, butyric anhydride, ethyl-2-ethylacetoacetate, valeric anhydride, 2-methylbutyric anhydride, nonanol, decanol, undecanol, dodecanol, propylene glycol propyl ether, propylene glycol ethyl ether, propylene glycol methyl ether, propylene glycol, phenyltrimethoxysilane, diphenylhexamethoxydisiloxane, diphenylhexaethoxydisiloxane, dioctyltetramethyldisiloxane, hexamethyltrisiloxane, tetramethyldisiloxane, decamethyltetrasiloxane, dodecamethylpentasiloxane, hexamethyldisiloxane, and mixtures thereof.

The invention belongs to the field of medicine chemical industry and particularly relates to a preparing method for parecoxib sodium. According to the method, benzaldoxime (compound I) and 1-phenyl-1-propyne (compound II) are subjected to an addition reaction under existence of a catalyst and an acid-binding agent to construct an isoxazole ring to obtain a parecoxib sodium intermediate (compound III); the compound III is subjected to a sulfonation and sulfonylation reaction to obtain a compound IV, and the compound IV and propionic anhydride react to form salt to obtain parecoxib sodium (compound V). According to the method, the dipole ring addition reaction is creatively adopted for preparing the compound III, common safe and low-toxicity reagents chlorosulfuric chlorosulfonic acid and ammonia water with relative stable nature are used to be subjected to the sulfonylation reaction, and the method has the advantages that the reaction condition is mild, operation is reasonable, selectivity is high, and product quality is high; raw and auxiliary materials in the reaction are low in price, and the production cost is reduced.

The invention discloses serial compounds with triptycene as a framework and in bridge connection with metalloporphyrin through pyrene tetrone and a preparation method therefor, and belongs to the photoelectric conversion material field. The compound molecular formula is C320H348N24M3. The structural formula is shown in the specification. Triptycene is subjected to nitration by utilization of concentrated nitric acid, and 2,6,14-trinitro-triptycene; after reduction, a reaction with propionic anhydride, p-toluenesulfonic acid and potassium nitrate is carried out, then sodium hydroxide is added, hydrolysis is carried out, and 2,6,14-triamino-3,7,15-trinitro-triptycene is prepared; after reduction of stannous chloride, ethanol and concentrated hydrochloric acid, 2,3,6,7,14,15-hexaamino triptycene hexachloro hydrochloride. 3,5-bis-tert-butyl benzaldehyde and pyrrole are reacted and porphyrin is prepared; porphyrin is reacted with cupric acetate and cupric nitrate solutions and nitro copper porphyrin is prepared; 4-amino-1,2,4-triazole is added, a reaction is carried out, and an amino substituted nitro copper porphyrin is prepared; after reduction, diamino copper porphyrin is prepared. 2,3,6,7,14,15-hexaamino triptycene hexachloro hydrochloride and 2,7-bis-tert-butyl pyrene-4,5,9,10- tetrone are reacted, and a compound 1 is prepared; the compound 1 is reacted with the diamino copper porphyrin, and a compound 2 is prepared; after metal removal, a reaction with a methanol solution of corresponding metal acetate is carried out, and the compound is prepared.

The invention discloses a preparation method for starch-based thin film with propionyl starch graft polylactic acid. The copolymer, which is obtained by that propionyl starch graft polylactic starch-based thin film is treated in a kneader by starch with a certain water content under a certain temperature and time, is added with propionic anhydride to react for a certain time and is grafted with lactic acid under the conditions of high temperature and high pressure, dissolves in acetone and is sprayed by a fluidized bed. The invention utilizes mechanical kneading and activation for the first time to obtain the propionyl of the starch and the graft copolymerization of the polylactic acid simultaneously with the help of the method of high temperature and high pressure, the whole reaction process is simple without any organic solvent, and the pollution to the environment is reduced. The grafting efficiency of the obtained copolymer is high. The modified starch thin film which is prepared by adopting the spray of the fluidized bed has good hydrophobicity as well as excellent mechanical performance, and can be used for the drug controlled-release carrier and the biodegradable material.

The invention discloses a method for preparing 4-(N-phenylpropionamide)-4-methoxymethyl-piperidine hydrochloride, which belongs to the technical field of preparation of medicinal intermediates. The 4-(N-phenylpropionamide)-4-methoxymethyl-piperidine hydrochloride is synthesized by using 1-phenyl-4-piperidone and aniline as initiative raw materials and by seven reactions. In raw materials used in the invention, trimethyl cyanato silane is used in place of potassium cyanide or sodium cyanide which is a highly toxic raw material to make the operation and management more convenient; potassium tert-butoxide and other alkalis are used in place of sodium hydride which is a dangerous and flammable reagent to improve the safety of scale-up production; propionic anhydride is used in place of highly irritant propionyl chloride to improve the safety, purity and yield of experiments; dimethyl sulfate is used in place of expensive methyl iodide to further control the production cost; and the high-pressure liquid chromatography (HPLC) purity of the obtained 4-(N-phenylpropionamide)-4-methoxymethyl-piperidine hydrochloride product can reach 99.7 percent, the single impurity content is less than 0.1 percent, the total yield can reach 23 percent, and the product is a hydrochloride which is favorable for storage and transport.

The invention discloses a device and method for preparing propionic anhydride through reactive distillation of acetic anhydride and propionic acid. The device comprises a reactor, a reactive distillation tower, a propionic anhydride refining tower, a condenser, a reboiler, a reflux tank, a kettle outlet tank, a pump and a pipeline. A process flow combining the reactive distillation tower with the reactor and the propionic anhydride refining tower is adopted. The method comprises the following steps: the acetic anhydride and propionic acid enter the reactor and react, and the acetic anhydride and propionic acid flowing into the reactive distillation tower react and are distilled on each layer of a tower plate of the section; the material flowing from the reaction section is distilled by a stripping section; the material rising from the reaction section is distilled by a distillation section, and 80-100% acetic acid is extracted from the tower top; the tower kettle discharge of the reactive distillation tower is pressurized and enters the propionic anhydride refining tower for distillation; several of acetic acid, acetic anhydride, propionic acid, propionic anhydride acetate and propionic anhydride are obtained from the tower top of the propionic anhydride refining tower, and the propionic anhydride with purity of 80-100% is obtained from the tower kettle of the distillation tower. The problems of unstable quality, relatively low yield and relatively low production efficiency of the products in batch production of propionic anhydride are solved.

The invention discloses a preparation method of a cyclooxygenase-2 inhibitor parecoxib. The method comprises the following steps that 1, benzaldoxime reacts with 1-phenylpropyne in the presence of tris(2-phenylpyridine)iridium (III), triethylamine and magnesium oxide under the illumination condition to obtain 5-methyl-3,4-diphenylisoxazole; 2, a stirring reaction is conducted on 5-methyl-3,4-diphenylisoxazole obtained in the first step and chlorosulfonic acid, dichloromethane extraction is conducted after the reaction is completed, a dichloromethane phase is directly added into ammonium hydroxide, an organic phase is separated, water washing, concentrating and ethanol recrystallization are conducted, and valdecoxib is obtained; 3, valdecoxib obtained in the second step reacts with propionic anhydride in the presence of triethylamine, and parecoxib is obtained. The preparation method of parecoxib is simple in step, high in yield and simple in posttreatment.

The invention discloses preparation methods of parecoxib sodium and intermediate thereof. The invention provides a preparation method of a parecoxib sodium intermediate I. The preparation method of the parecoxib sodium intermediate I comprises the following step: in the presence of a catalyst, performing condensation reaction on valdecoxib III and propionic anhydride to obtain the parecoxib sodium intermediate I, wherein the catalyst is one or more of benzenesulfonic acid, p-toluenesulfonic acid, methanesulfonic acid and sulfamic acid. The preparation method is simple in reaction and post-treating operation, high in yield and low in cost; the purity of the prepared intermediate product is high and can reach 99.80% or above, and the content of specific impurity valdecoxib reaches 0.02% or below and can meet the standard of an original researching manufacturer; therefore, the preparation method is suitable for industrial production. The purity of parecoxib sodium prepared from the parecoxib sodium intermediate I prepared by the preparation method provided by the invention can reach 99.80% or above and the content of the specific impurity valdecoxib reaches 0.01% or below and is higher than the standard of the original researching manufacturer.

The invention provides a method for synthesizing TNPP and TAPP at high yield and high efficiency and belongs to the technical field of chemical synthesis. The method provided by the invention is characterized in that a small amount of acetic anhydride or propionic anhydride is added to serve as a catalyst in the reaction process of nitrobenzaldehyde and pyrrole, so that the reaction speed is effectively improved and the reaction is performed rightwards to the maximum extent; hot pyrrole is adopted for dissolving and purifying the TNPP to obtain a TNPP product with high purity; in the process of synthesizing the TAPP, a strong reducer tin chloride is adopted for ammonifying the TNPP, and trichloromethane capable of dissolving the TAPP is adopted for efficiently separating the TAPP from an organic phase by adopting a Soxhlet extraction method, so that the purity and the yield of the TAPP are effectively improved.

The invention relates to a preparation method of low-propionyl-content cellulose acetate propionate mixed ester. Cellulose is prepared from, by weight, 650 g of wood pulp, 296 g of propionic acid, 2250 g of acetic acid, 118 g of acetic anhydride, 2070 g of propionic anhydride and 19.5-52 g of catalysts. The ratio of liquid acid catalysts to heteropolyacid catalyst is between 4 to 6 and 6 to 4. The preparation method includes the steps of conducting activating, the esterification reaction, mixing, magnesium acetate solution adding, hydrolysis and chromatography, sequentially conducting conventional filtering, washing and drying, and obtaining the finished product. The method has the advantages that the propionyl content of the obtained cellulose acetate propionate finished product is 15-20%, and the acetyl content is smaller than 22-30%; the mixture of liquid acid and heteropolyacid is selected for the catalysts, and therefore the sulfuric acid consumption is lowered, the corrosion to a technological device and the pollution to the environment can be reduced, and technological safety is improved; meanwhile, by adding heteropolyacid, the esterification reaction is accelerated, and the hydrolysis reaction is more precise and controllable.

The invention relates to an acrylamide copolymer containing halothane and phosphoric acid ester as well as a preparation method and the application thereof. The preparation method comprises the steps of: (1) dissolving monomer, crosslinking monomer and non-fluoro long-chain monomer of the acrylamide copolymer containing halothane and phosphoric acid ester and emulsifier in deionized water and solvent for ultrasonically pre-emulsifying for 1-5h to obtain milk-white pre-emulsion; (2) under the protection of N2, heating 1 / 3 of the pre-emulsion to 60-90 DEG C, slowly dropping an initiator aqueous solution for initiating reaction, stopping dropping after the emulsion has blue fluorescence, combining the residual initiator aqueous solution with the pre-emulsion, slowing dropping the combined residual initiator aqueous solution and pre-emulsion into reaction liquid, stopping reaction after continuously reacting for 1-5h at 60-90 DEG C, and cooling down to the room temperature to obtain the required emulsion PFPA (Per Fluoro Propionic Anhydride). In the invention, cotton fabric processed by the copolymer emulsion has excellent performances of resisting water, oil and flame, the processing process is simple, and greater development potency is provided.

The invention discloses a preparation method and application of a clethodim intermediate. The preparation method of the clethodim intermediate comprises the step of directly reacting a compound A withpropionyl chloride or propionic anhydride under the action of a catalyst to prepare a compound D, wherein the catalyst is a ZSM-5 molecular sieve or / and an H-ZSM-5 molecular sieve. A special catalystis selected, the compound D is prepared from the compound A in one step, operation is easy and convenient, catalyst selectivity is high, side reactions are few, the reaction process is easy to control, participation of water is not needed in the reaction process, a large amount of water cannot be introduced, and therefore hydrolysis side reactions cannot happen, the byproduct content is further reduced, and the product purity is improved. The reaction does not need intermediate washing, layering, rearrangement and other operations, thereby simplifying the process flow, shortening the reactiontime and enhancing the production efficiency. The yield of the compound D is high and is 87% or above, and the purity is high and is 85% or above.

The invention relates to a preparation method of cellulose acetate propionate mixed ester with high propionyl content. Cellulose is prepared from the following components in parts by weight: 650g of wood pulp, 2630g of propionic acid, 40g of acetic anhydride, 2070g of propionic anhydride and 19.5-52g of a catalyst, wherein the ratio of a liquid acid catalyst to heteropolyacid catalyst is 4:6 to 6:4. The preparation method comprises the steps of activating, carrying out esterification reaction, mixing, adding a magnesium acetate solution, hydrolyzing and carrying out chromatography; and then, sequentially carrying out conventional filtration, washing and drying to obtain a finished product. The preparation method has the advantages that the finished product of cellulose acetate propionate, prepared by using the method, contains more than or equal to 46% of propionyl content and less than or equal to 2% of acetyl and is stable in performance; the catalyst is a mixture of liquid acid and heteropolyacid, so that the consumption of sulfuric acid is reduced, furthermore, corrosion to process equipment and environment pollution can be reduced, and the process safety can be improved; and meanwhile the heteropolyacid is additionally applied, so that the esterification reaction is accelerated, and hydrolysis reaction is more precise and controllable.

The invention relates to a compound and a preparation method thereof, and specifically relates to an intermediate for synthesizing pramipexole dihydrochloride and a preparation method thereof. The intermediate is easy to purify. The synthesis of the intermediate comprises the following steps: subjecting (s)-2,6-diamino-4,5,6,7-tetrahydrobenzothiazole to carry out reactions with propionic anhydride, and then reducing the reaction products with a reductant so as to obtain the intermediate. The whole reaction process does not contain any intermediate treatment, and the preparation method has the advantages of simple reaction process, mild reaction conditions, high safety, high yield, and suitability for industrial production.

The invention discloses a synthesis method and application of intermediates of a sulindac analogue, relating to intermediates of a sulindac analogue. The intermediates are 5-fluoro-2-metyl-3-indene ethyl acetate (5a) and 5-fluoro-2-metyl-3-indene acetic acid (5b). The synthesis method comprises the following steps of: subjecting 4-fluorobenzaldehyde as an initial raw material, propionic anhydride as a solvent and propionic anhydride to a perkin reaction to obtain 4-fluoro-2-metyl-methylcinnamic acid; catalyzing the 4-fluoro-2-metyl-methylcinnamic acid with palladium carbon with the palladium content of 5-20 percent and reducing in the hydrogen gas atmosphere to obtain 3-(4-fluorine phenyl)-2-methyl propionate; subjecting the 3-(4-fluorine phenyl)-2-methyl propionate to the intramolecilar friedel-crafts acyl browning reaction under the action of polyphosphoric acid under the heating condition to form 6-fluoro-2-methyl indene ketone; and subjecting the 6-fluoro-2-methyl indene ketone and halogenated acetate to reformatsky reaction under the action of the activated zinc powder to obtain a crude product and eliminating the crude product in an acid solution to obtain 5-fluoro-2-metyl-3-indene acetate. The intermediates can be used for preparing novel sulindac analogues with anticancer activity.

For solving the problems that a lithium-manganese primary battery in the prior art generates gas and influences the discharge characteristic under a high temperature environment, the invention provides a lithium-manganese primary battery, which includes a cathode, an anode and an electrolyte. The cathode includes MnO2. The electrolyte includes an additive. The additive includes an acid anhydride compound being one or more of: maleic anhydride, methyl maleic anhydride, dimethyl maleic anhydride, succinic anhydride, glutaric anhydride, methyl succinic anhydride, dimethyl succinic anhydride, acetic anhydride, propionic anhydride and butyric anhydride. By means of the specific acid anhydride compound, the high-temperature storage performance of the lithium-manganese primary battery is effectively improved.

The invention discloses a method for synthesizing a 2,4,5-trimethoxyethylphenylketone intermediate of alpha-asarin, which is characterized by comprising the following steps of: directly reacting 2,4,5-trimethoxybenzene, which servers as a raw material, with propanoic acid or propionic anhydride under the action of polyphosphoric acid, or a mixture of phosphoric acid and phosphoric anhydride, or a mixture of the polyphosphoric acid, the phosphoric acid and the phosphoric anhydride; and performing hydrolysis to obtain the 2,4,5-trimethoxyethylphenylketone. The product can be used as the raw material or the intermediate of the alpha-asarin or the raw material for synthesizing other medicaments, and also can be used as spices. The method of the invention has the advantages of simple process, low cost, high product quality, high yield and the like and is safe and reliable in operation and suitable for industrial production. The method can effectively solve the problems of complicated operation and the like of the synthesis of the 2,4,5-trimethoxyethylphenylketone intermediate of the alpha-asarin.

The invention discloses hydrophobic enhanced calligraphy and painting paper and a making method thereof and belongs to the technical field of paper making. The hydrophobic enhanced calligraphy and painting paper disclosed by the invention comprises calligraphy and painting paper and a hydrophobic modification nano cellulose coating, wherein the hydrophobic modification nano cellulose coating is formed on the surface of the calligraphy and painting paper; hydrophobic modification nano cellulose is nano cellulose prepared by firstly performing oxidation pretreatment on cellulose by using a 2,2,6,6-tetramethyl piperidine oxide to obtain cellulose with carboxyl, and by further performing high-pressure homogenization; and the nano cellulose is further subjected to hydrophobic modification by using a two-step method, namely, in a first step, glutaric anhydride and propionic anhydride are adopted as composite anhydride as a reagent for esterification modification on the nano cellulose, and ina second step, 1-tridecylamine and n-decylamine are reacted with the nano cellulose after esterification modification through an electrostatic adsorption function to form a complex. As the nano cellulose used in the paper is small in size and is easy to deposit on the surface of the paper or infiltrate into pores, the vapor barrier performance and t he hydrophobicity of the paper can be improved,and in addition, the strength property of the calligraphy and painting paper can be remarkably improved.

The invention discloses a method for preparing Parecoxib. The method for preparing the Parecoxib comprises the following steps of: performing sulfonation reaction on 1,2-diphenyl butanone serving as a raw material to obtain 1-phenyl-2-(4-sulfo phenyl)butanone; in the presence of alkali, performing condensation on the 1-phenyl-2-(4-sulfo phenyl)butanone and acetylchloride to prepare 1-phenyl-2-(4-sulfo phenyl)-2-acetyl butanone; performing cyclization on the 1-phenyl-2-(4-sulfo phenyl)-2-acetyl butanone and hydroxylamine hydrochloride to obtain 4-(5-methyl-3-phenyl-4-isoxazole)benzenesulfonic acid; performing chlorination and ammonolysis reaction to prepare Bextra; and reacting the Bextra with propionic anhydride to synthesize the Parecoxib. In the method, the raw materials are readily available and reaction conditions are not rigorous. The method is easy and convenient to operate and has certain industrialized value.

The invention discloses a cationoid esterified starch-grafted and modified acrylic resin paper waterproof agent. A preparation method is characterized in that starch is subjected to acidolysis and oxidation treatment, then is subjected to an esterification reaction with propionic anhydride to prepare the esterified starch, then the esterified starch is subjected to graft copolymerization with an acrylic acid monomer and a cationic monomer to obtain the cationoid esterified starch-grafted and modified acrylic resin paper waterproof agent. The cationoid esterified starch-grafted and modified acrylic resin paper waterproof agent can realize a purpose of waterproof paper by internal sizing and surface sizing.