101 results about "Chloroacetaldehyde" patented technology

The invention relates to a method for preparing praziquantel, which is a one-pot method and comprises the following steps: performing an ammonolysis reaction of chloroacetaldehyde dimethyl acetal and an ammonia aqueous solution to generate aminoacetaldehyde dimethyl acetal; performing a condensation reaction of beta-phenylethylamine and chloroacetyl chloride in an organic solvent in alkaline environment to generate an intermediate 1; performing a condensation reaction of the intermediate 1 and the aminoacetaldehyde dimethyl acetal in an organic solvent to generate an intermediate 2; performing cyclization of the intermediate 2 in the presence of an acidic catalyst to generate an intermediate 3; performing a reaction of the intermediate 3 and cyclohexanecarboxylic acid chloride in an organic solvent in alkaline environment, and performing solvent crystallization to obtain the target product of praziquantel.

The invention provides a 2-deoxy-D-ribose-5-phosphate aldolase (DERA enzyme) which is capable of catalyzing an aldol condensation reaction at high performance. Compared with a wild type escherichia coli DERA enzyme, the 2-deoxy-D-ribose-5-phosphate aldolase has improved substrate resistant ability and more efficient catalytic ability. If the DERA enzyme provided by the invention is used as a catalyst, the problem of the inactivation of the DERA enzyme caused by a high-concentration chloroacetaldehyde substrate can be solved, and simultaneously, the volume of addition of the enzyme in the production process is reduced. The invention also provides a nucleic acid for coding the DERA enzyme, a recombinant expression vector containing the nucleic acid, a recombinant expression transformant containing the recombinant expression vector, a method for preparing a recombinant DERA enzyme and a catalyst for forming an optically active statin intermediate through catalysis.

The invention discloses an aldolase mutant, a coding gene thereof and an application of the aldolase mutant in production of statins intermediates, and belongs to the technical field of molecular biology. The amino acid sequence of the aldolase mutant is as shown in SEQ ID NO. 1. According to the invention, on the basis of thermophilic bacteria Thermoga maritima wild aldolase, site-specific mutagenesis is introduced into the coding gene of the thermophilic bacteria Thermoga maritima wild aldolase, a codon (TTT) for coding phenylalanine at the 184 site is mutated into a codon (ATT) for coding isoleucine, and serine (Ser) at the 233 site is mutated into alanine (Ala). The activity of the obtained aldolase mutant in an acetal reaction by using acetaldehyde and chloroacetaldehyde as substratesis remarkably improved, catalytic efficiency is improved by 0.86 times, the mutant has a good industrial application prospect, and the problems of low aldolase catalytic conversion rate, insufficientactivity, poor substrate affinity and the like of wild thermophilic bacteria are solved.

The invention discloses a preparation method of (4R-cis)-6-chloromethyl-2, 2-dimethyl-1, 3-dioxane-4-acetic acid isopropyl ester. The preparation method has the advantages that chloroacetaldehyde and acetaldehyde serve as reaction substrates to complete a condensation reaction under the action of aldolase, an open-loop esterification reaction between an oxidative obtained product and isopropanol is achieved in the presence of a catalyst, and ester exchange between the product and 2, 2-dimethoxy propane is completed to obtain a target product, so that synthetic route is short, highly toxic products are not used in the whole reaction process, and raw materials are low in cost.

The invention discloses an Acalabrutinib synthesizing method which comprises the steps: utilizing L-proline derivative compound shown in a formula 1 and 2-chloro-2-formyl acetonitrile as beginning rawmaterials to directly condense and cyclize to obtain a compound in a formula 2; after bromination, reacting with cheap chloroacetaldehyde dimethyl acetal to obtain intermediate compound in a formula3; obtaining key intermediate compound shown in a formula 6 through hydrolysis and cyclization reaction; then performing Suzuki coupling with borate intermediate compound shown in a formula 8; then de-protecting and salifying to obtain compound shown in a formula 10; finally, performing condensation with tetrolic acid to obtain a final product Acalabrutinib shown in a formula 11. The path has theadvantages of simpleness in operation, higher total yield and suitability for enlarged production, and a purity of the obtained product is also higher.

The invention provides a mercaptoacetone oxime cleaner production method and system. The method at least comprises the following steps that (1) aldoxime and a solution containing chloride ions are added into an anode chamber of an electrolytic cell, an electrolyte solution is added into a cathode chamber, energization is conducted for electrolysis, and a solution containing chloroacetaldehyde oxime is formed in the anode chamber; and (2) the solution containing the chloroacetaldehyde oxime is mixed and reacted with methyl mercaptan, a solution containing mercaptoacetone oxime is obtained, separated and purified, and a finished mercaptoacetone oxime product is obtained. Hypertoxic chlorine is not used, brine waste is effectively avoided, the environment protection problem caused by waste salts in existing mercaptoacetone oxime production processes is solved, the raw material consumption is effectively reduced, generated hydrogen can be used as clean fuel, and the raw material utilization rate is effectively improved.

The invention discloses a preparation method of chloroacetaldehyde dimethyl acetal. The method adopts vinyl acetate, anhydrous methanol and chlorine as reaction raw materials, adopts a step-by-step feeding one-pot boiling method and also adds a polymerization inhibition inducing agent, so that the reaction raw materials can maximally participate in the reaction to generate a target product, the generation of side products can be reduced, and the prepared product is high in yield and high in purity. The preparation method of the invention is controllable in conditions, simple and easy in product separation method and convenient in industrialized operation.

The invention discloses a high performance liquid chromatography-fluorescence detection method for 3-MCPD. The method comprises the following steps: (1) treating a 3-MCPD aqueous solution, and cracking the 3-MCPD into chloroacetaldehyde; (2) removing excessive periodate, and eliminating side reaction; (3) carrying out fluorescence derivation reaction, namely enabling the chloroacetaldehyde to react with a fluorescence derivation reagent so as to generate a target material with a fluorescence effect; and (4) performing HPLC-FLD measurement, namely separating the target material, and quantifying the 3-MCPD according to the chromatographic peak area, wherein the fluorescence derivation reagent refers to an o-amino binary N-heterocyclic compound. According to the method disclosed by the invention, a type of novel fluorescence derivation reagents with convenient and readily available materials, high selectivity, high fluorescence efficiency and high hydrophobicity can be used for high performance liquid chromatography-fluorescence detection of 3-MCPD, so that the target product has a good retention behavior in the reversed phase liquid chromatography, and the accuracy and sensitivity of the test method are improved.

The invention discloses a method for synthesizing chloroacetaldehyde through catalysis of aqueous solution of aldehyde. In the method, the aqueous solution of aldehyde is taken as a raw material, and the aldehyde is subjected to chlorination by controlling reaction temperature in the presence of a single or mixed catalyst; and after the reaction is finished, the product is subjected to distillation or suction filtration, and high-purity chloroacetaldehyde is obtained. The method has the advantages of high yield and light environmental pollution, and can be applied to preparation of a small amount of chloroacetaldehyde in a laboratory and industrial production.

The invention relates to a synthetic method of ethyl 3-aldehyde-6-chloroimidazo[1,2-a]pyridine-8-formate. The method comprises the following steps: carrying out a substitution reaction on ethyl 2-aminonicotinate and N-chlorosuccinimide in a certain solvent at normal temperature to prepare ethyl 2-amino-5-chloronicotinate; and reacting2-amino-5-chloronicotinate with N,N-dimethylformamide dimethyl acetal to prepare an intermediate, reacting the intermediate with chloroacetaldehyde in a certain solvent at 0-100DEG C without purifying the intermediate, cooling, and drying to obtain ethyl 3-aldehyde-6-chloroimidazo[1,2-a]pyridine-8-formate. The method has the advantages of easily available reaction raw materials, reasonable price, mild reaction conditions, easy operation, easy control and simple post-treatment, and the above obtained product has the advantages of stable quality and high purity.

The invention relates to a process for preparing chloroacetaldehyde acetals of monohydric, dihydric or higher-functionality aliphatic alcohols, in which the chloroacetaldehyde acetal is obtained from an aqueous chloroacetaldehyde solution in the presence of the alcohol to be acetalized and an acid catalyst by azeotropic removal of water with the aid of a solvent, wherein the solvent is a halogenated solvent.

The invention discloses a new technology for producing aminoacetaldehyde dimethyl acetal. Chloroacetaldehyde dimethyl acetal is firstly synthesized into aminoacetaldehyde dimethyl acetal by using ammonia solution containing carbon dioxide, aminoacetaldehyde dimethyl acetal and carbon dioxide are then converted to hydroxymethyl aminopropyl formic acid, aminoacetaldehyde dimethyl acetal is preventedfrom continuously reacting with chloroacetaldehyde dimethyl acetal to generate secondary and tertiary amine, after deamination, hydroxymethyl propylcarbamic acid is decomposed into aminoacetaldehydedimethyl acetal and carbon dioxide after high temperature and acid aqueous reflux. After recovering carbon dioxide, aminoacetaldehyde dimethyl acetal hydrochloride is obtained, and then aminoacetaldehyde dimethyl acetal hydrochloride is neutralized, distilled and rectified to obtain high purity aminoacetaldehyde dimethyl acetal.

The invention relates to a synthetic method for 2-acetyl thiazole. The synthetic method comprises the following steps: firstly, preparation of 2-amino thiazole is carried out, namely, toluene, thiourea and chloroacetaldehyde are mixed, a reaction is carried out with stirring at a constant temperature, and 2-amino thiazole is prepared; secondly, preparation of 2-bromo thiazole is carried out, namely, 2-amino thiazole is dissolved in sulfuric acid, cooling is carried out, a sodium nitrite aqueous solution is added drop by drop slowly at a controlled temperature after concentrated nitric acid is added drop by drop, stirring is carried out continuously, a reaction is carried out, the solution after the reaction is added in a mixed solution of sodium bromide and copper sulphate, a bromination reaction is carried out, and 2-bromo thiazole is prepared; thirdly, preparation of 2-acetyl thiazole is carried out, namely, 2-bromo thiazole is added in a butyllithium solution, stirring is carried out, then ethyl acetate is added, a reaction is carried out, and 2-acetyl thiazole is prepared. The acetylation step of 2-bromo thiazole is improved, the reaction raw material ratio and the reaction temperature are optimized, the high yield of the reaction is achieved, safe and reliable operation of the experiment is ensured effectively, and unexpected technical effects are achieved.

The invention discloses a novel synthesis method of benzothiacyclopentadiene, and belongs to the technical field of synthesis. The method comprises the following steps that: under an alkaline condition, chloroacetaldehyde and thiophenol undergo a Williamson condensation reaction to obtain thiophenyl acetaldehyde, the thiophenyl acetaldehyde undergoes a cyclization and dehydration reaction with a dehydrating agent under an acidic condition, water is added, layering is performed, an organic layer is taken, and reduced pressure distillation is performed to obtain the target product benzothiacyclopentadiene. The method has the advantages of simple operation, mild reaction, easy realization of industrialization, and high product yield.

The invention discloses a synthetic method of 2-chloroethyl hydrazono methyl formate. According to the synthetic method, dimethyl carbonate, hydrazine hydrate, chloroacetaldehyde, methyl formate, p-nitrobenzaldehyde, acetic anhydride, pyrrole, pyridine, zinc chloride, and terephthalaldehyde are taken as main raw materials; dimethyl carbonate and hydrazine hydrate are subjected to oxidation reaction under the effect of catalyst AZO-CMP-1; chloroacetaldehyde and methyl formate addition substation is carried out so as to obtain the target product 2-chloroethyl hydrazono methyl formate; in oxidation reaction, the catalyst is a liquid solid double-phase catalyst system, and is extremely high in catalytic activity, selectivity, and recycling stability; high conversion degree is achieved; production separation purifying is easy; and product yield is high.

The invention provides a preparation method for 2,5-dihydroxyl-1,4-dithiane. The preparation method comprises the steps of adjusting pH of chloroacetaldehyde, preparing a sodium hydrosulfide solution,dropwise adding part of sodium hydrosulfide solution, carrying out a dropwise adding reaction, and carrying out aging. The 2,5-dihydroxyl-1,4-dithiane prepared by the method has a yield not lower than 90.0%; the appearance of the 2,5-dihydroxyl-1,4-dithiane prepared by the method is white-like or yellowish powder, and the content of dithiane is not lower than 97.0%; the moisture content is not higher than 0.5%; the clarity is of colorless transparent liquid (N,N-dimethylformamide serves as a solvent); and a melting range is 135.0 DEG C to 150.0 DEG C.

The invention relates to a synthetic method of ethyl 3-aldehyde-6-bromoimidazo[1,2-a]pyridine-8-formate. The method comprises the following steps: carrying out a substitution reaction on ethyl 2-aminonicotinate and N-bromosuccinimide in a certain solvent at normal temperature to prepare ethyl 2-amino-5-bromonicotinate; and reacting2-amino-5-bromonicotinate with N,N-dimethylformamide dimethyl acetal at 30-150DEG C to prepare an intermediate, reacting the intermediate with chloroacetaldehyde in a certain solvent at 60-160DEG C without purifying the intermediate, cooling, and drying to obtain ethyl 3-aldehyde-6-bromoimidazo[1,2-a]pyridine-8-formate. The method has the advantages of easily available reaction raw materials, reasonable price, mild reaction conditions, easy operation, easy control and simple post-treatment, and the above obtained product has the advantages of stable quality and high purity.

The invention belongs to the field of organic synthesis and in particular relates to a synthetic method of 3,6-dichloroimidazo[1,2-a]pyridine. The synthetic method comprises the following steps: by using 2-amino-5-chloropyridine, a chloroacetaldehyde water solution and N-chlorosuccinimide as raw materials, continuously reacting at 35-115 DEG C in proper solvents under the action of alkali to generate a crude product of 3,6-dichloroimidazo[1,2-a]pyridine and purifying the crude product, thus obtaining pure 3,6-dichloroimidazo[1,2-a]pyridine, wherein the ratio of amount of substance of 2-amino-5-chloropyridine and the chloroacetaldehyde water solution is 1 to (0.9-3.0), and the ratio of amount of substance of 2-amino-5-chloropyridine and N-chlorosuccinimide is 1 to (0.7-2.5). The synthetic method has the beneficial effects that the reaction raw materials are easier to obtain; the price is reasonable; the reaction conditions are mild; the synthetic method is easy to operate and control and is simple in after-treatment; the product has stable quality and high purity.

The invention relates to the technical field of synthesis of medical intermediates, in particular to a preparation method of a baloxavir intermediate, wherein the baloxavir intermediate is 2,-(2-aminoethoxy)-1, 1-dimethoxyethane. The synthesis route of the baloxavir intermediate specifically comprises the following steps: 1) mixing an alkaline reagent and ethanolamine to obtain a mixed solution, and heating; 2) adding chloroacetaldehyde dimethyl acetal into the mixed solution, stirring, and reacting; and 3) after the reaction is finished, adding ice water and dichloromethane for post-treatment, concentrating an organic phase, and rectifying to obtain the 2,-(2-aminoethoxy)-1, 1-dimethoxyethane. The method is high in product purity, low in cost, simple to operate, mild in condition and suitable for industrial popularization.

The invention discloses a preparation method of amino aminoacetaldehyde dimethyl acetal, comprising steps of firstly adding chloroacetaldehyde dimethyl acetal and methyl alcohol in a pressure reaction kettle, mixing them uniformly; then adding liquid ammonia, heating up to 150 degrees centigrade for high pressure reaction; adding intermediate materials into a concentration kettle, carrying out distillation several times, reducing the pressure of distillation each time until the methyl alcohol is recovered successfully, and centrifugally filtering the solution; adding sodium hydroxide in the centrifugal liquid to regulate its Ph value; conducting rectification and extraction dehydration under a normal pressure, and carrying out a secondary rectification after purification, maintaining the secondary rectification as a pressure reduced rectification to ensure safety until qualified distillate is collected, thereby obtaining the product amino aminoacetaldehyde dimethyl acetal. The preparation method is simple in process and is applicable to industrialization, with high product purity.

The invention discloses a preparation method of aziridine cross-linked N halamine type antibacterial PVA (polyvinyl alcohol) sponge, and belongs to the field of biomedical materials. The preparation method comprises the following steps: firstly, reacting PVA with chloroacetaldehyde and glyoxylic acid to obtain PVA containing carbon-chlorine bonds and carboxyl groups, then reacting with 1-chloro-2, 2, 5, 5-tetramethyl-4-imidazolinone to obtain PVA molecules with halamine groups, further adopting an aziridine cross-linking agent for cross-linking, emulsifying and forming, and freeze-drying to obtain the N halamine type antibacterial PVA sponge. The prepared N halamine type PVA sponge has good antibacterial performance and liquid absorption performance, and can be used as a hemostatic material and a wound dressing; the preparation process is simple, and the prepared sponge material is lasting in antibacterial property, safe and non-toxic, overcomes the defects that an existing antibacterial PVA sponge is complex in preparation process, poor in antibacterial durability and poor in inorganic antibacterial agent safety, and is suitable for market popularization and application.

The present invention belongs to the field of organic synthesis, and particularly relates to a synthesis method for 3-aldehyde imidazo-[1, 2-alpha] pyridine-8-ethyl formate, which comprises the following steps of obtaining a purification-free intermediate through the dimethyl acetal reaction between 2-amino-nicotinic acid ethyl ester and N, N-dimethyl formamide; reacting the intermediate with chloroacetaldehyde at 0-100 DEG C in a certain solvent, cooling the solvent after the reaction, adding alkali of a certain amount in the solvent to precipitate solids, and finally obtain 3-aldehyde imidazo-[1, 2-alpha] pyridine-8-ethyl formate after the dissolving, drying and rotary evaporation process. The raw materials of the method are readily available, reasonable in cost, mild in reaction conditio, easy to operate and control, and simple in post-processing. Products obtained through the method are stable in quality and high in purity.