27 results about "Ethyl chloroformate" patented technology

The invention belongs to the technical field of chemical synthesis of medicines, and particularly relates to a preparation method of a CETP inhibitor Obicterapib. The invention provides three preparation schemes. According to the scheme I, 2-phenyl pentenoate and (R)-N-(1-phenethyl)-4-(trifluoromethyl) aniline are subjected to a reaction, and a target compound Obicterapib is prepared through hydrolysis, cyclization, acylation, asymmetric chiral amine and other multi-step reactions; according to the second scheme, 4-halogenated benzotrifluoride reacts with (R)-3-amino valeronitrile, then nitrile hydrolysis is carried out, the product reacts with ethyl chloroformate, bis (trifluoromethyl) benzyl bromide, bis (pinacolato) diboron and ethyl 4-bromobutyrate, and finally hydrolysis is carried out to prepare the target compound Obictapib. According to the third scheme, (R)-3-(4-trifluoromethyl-phenyl amino)-valeric acid is substituted by amino to obtain a compound (R)-3-[4-(trifluoromethyl) phenyl amino]-valeric acid amide, then the compound (R)-3-[4-(trifluoromethyl) phenyl amino]-valeric acid amide reacts with ethyl chloroformate, bis (trifluoromethyl) benzyl bromide, bis (pinacolato) diboron, ethyl 4-bromobutyrate and 5-bromine-2-chloropyrimidine, and finally hydrolysis is conducted to prepare the target compound Obictapib.

The invention provides a method for detecting ethyl chloroformate, 1,3-bromochloropropane and ethyl methylcarbamate impurities in an eptazocine intermediate (-)-(1S-6S)-2,3,4,5,6,7-hexahydro-1,4-dimethyl-1,6-methylene-1hydro-4-phenylin-10-methoxy ether (compound 2). The method is rapid, accurate and has a low detection limit. The method can effectively control the content of ethyl chloroformate, 1,3-bromochloropropane and ethyl methylcarbamate that may remain in compound 2, thereby ensuring the safety of the use of an eptazocine hydrobromide preparation product further prepared from an eptazocine hydrobromide raw material.

This invention relates to the field of spray system technology, and more particularly to an alkaline spray system for the production of ethyl chloroformate, comprising the following steps: S1, adding tetramethylammonium hydroxide to water, heating to room temperature, stirring until completely dissolved, adding modified sodium metasilicate, disodium ethylenediaminetetraacetate, and sodium lignosulfonate, controlling the temperature and stirring, filtering to obtain an alkaline solution; S2, turning on the power to the control system, ensuring the control system operates normally, setting the operating parameters of the spray system, starting the alkaline solution pump, drawing the alkaline solution from the storage tank, conveying it through pipelines to the spray heads, adjusting the pump's output flow rate, and starting intermittent, uniform spraying of the alkaline solution. The waste liquid after spraying flows through pipelines into a sedimentation tank for post-treatment. The alkaline spray system of this invention can significantly improve the purification efficiency of acidic gases, heavy metal ions, and organic pollutants in waste gas.

The invention provides a preparation method of methimazole, and relates to the field of medicinal chemistry. The method comprises the following steps: by taking 1-methylimidazole, ethyl chloroformate and sulfur as raw materials, reacting under an alkaline condition to generate an intermediate 3-methyl-2-thio-2, 3-dihydro-1H-imidazole-1-carboxylic acid ethyl ester; and then hydrolyzing under an alkaline condition to generate methimazole. The method is simple to operate, mild in condition and suitable for large-scale industrial production.

The invention relates to a synthetic method of 2-diphenylmethyl pyrrolidine or an acid salt of 2-diphenylmethyl pyrrolidine. In order to solve the problems of easy ring opening and low yield in the prior art, the invention provides a synthetic method of 2-diphenylmethyl pyrrolidine or an acid salt thereof, which comprises the following steps: in the presence of an alkaline reagent, performing amidation and esterification reaction on a compound pyrrole-2-formic acid as shown in a formula II and ethyl chloroformate in an ROH solvent to obtain a compound as shown in a formula III; r in the ROH solvent is alkyl; performing Grignard reaction with phenyl magnesium bromide to obtain a compound as shown in a formula IV; carrying out reduction reaction on the compound shown in the formula IV under the catalytic action of trifluoroacetic acid and triethyl silane to obtain a compound shown in a formula V; and carrying out hydrolysis reaction on the compound in the formula V under an alkaline condition to obtain the compound 2-diphenylmethylpyrrolidine in the formula I or the acid salt thereof. According to the method, ring-opening impurities can be effectively avoided, the yield is increased to 95% or above, and the purity reaches 99% or above.

The invention discloses a preparation method of L-2, 4-diaminobutyric acid dihydrochloride, which comprises the following steps: (1) taking L-homoserine as an initial raw material, and reacting with concentrated hydrochloric acid in the presence of a zinc chloride / ferrous chloride synergistic catalyst to prepare L-2-amino-4-chlorobutyric acid hydrochloride; (2) after neutralization, carrying out an acylation reaction with ethyl chloroformate to generate N-ethoxycarbonyl-L-4-chlorobutyric acid; (3) carrying out esterification with ethanol so as to obtain N-ethoxycarbonyl-L-4-chlorobutyl amino acid ethyl ester; (4) under the catalysis of sodium iodide, carrying out nucleophilic substitution reaction with phthalimide potassium salt, and cooling, crystallizing and purifying the key intermediate by dropwise adding water to obtain L-2-[(ethoxycarbonyl) amino]-4-phthalimide ethyl butyrate; and (5) finally, hydrolyzing for deprotection, and concentrating and crystallizing to obtain the L-2, 4-diaminobutyric acid dihydrochloride. The method has the advantages of mild reaction conditions, simplicity and convenience in operation, high total yield and the like, and is suitable for large-scale industrial production.

The application relates to the technical field of tail gas treatment, in particular to a tail gas capturing and treating system applied to ethyl chloroformate synthesis, which comprises the following steps: S1, condenser pretreatment of tail gas; S2, falling film absorption, to obtain concentrated hydrochloric acid and tail gas after falling film absorption; S3, catalytic decomposition of phosgene, to obtain dilute hydrochloric acid and tail gas after catalytic decomposition; and S4, secondary series alkaline washing is carried out, and the dilute lye is used for circular spraying and is discharged through an induced draft fan. In the application, ethanol, ethyl chloroformate and other low-boiling-point substances in the tail gas are recovered through condenser pretreatment, the condensate is returned to a production system for recycling, raw material waste is reduced, and production cost is lowered. Hydrogen chloride is efficiently absorbed and converted into concentrated hydrochloric acid and dilute hydrochloric acid, which are used in the next section for recycling or external sale, resource reuse is realized, and harmful gas emission is reduced.

The synthesis method comprises the following steps: by taking 4-chloro-2-fluoroaniline and ethyl trifluoroacetoacetate as initial raw materials, carrying out condensation reaction to obtain a first intermediate, then carrying out cyclization reaction on the first intermediate and cyanate to obtain a second intermediate, and finally, carrying out cyclization reaction on the second intermediate and the cyanate to obtain the difluoropyrithiobac-methyl intermediate. And finally, carrying out methylation reaction with a methylation reagent to obtain the dithiobac-methyl intermediate. According to the synthesis method disclosed by the invention, ethyl trifluoroacetoacetate is adopted to replace ethyl chloroformate to carry out condensation reaction with 4-chloro-2-fluoroaniline, so that the use of highly toxic ethyl chloroformate can be avoided, and the operation safety is greatly improved; and the first intermediate obtained by condensation can be subjected to a cyclization reaction with low-price cyanate to prepare a second intermediate, so that the use of high-price ethyl 3-amino-4, 4, 4-trifluorocrotonate can be avoided, the production cost is greatly reduced, and the method is suitable for industrial mass production.

The invention discloses a production process method of ethyl chloroformate, which specifically comprises the following steps: S1, placing absolute ethyl alcohol in a reactor, cooling, and adding a low-temperature catalyst; s2, introducing phosgene into the reactor while maintaining the introduction temperature; s3, after phosgene is completely introduced, heating to a reaction temperature, keeping the temperature for reaction, and purifying after the reaction is finished to obtain ethyl chloroformate. The prepared low-temperature catalyst is used for reaction, so that the reaction yield and purity are improved, and the method has a wide application prospect.

The application discloses a spiromesifen derivative, belongs to the field of crop disease and pest control, and has the structure shown in the following formula 1001, a preparation method thereof is as follows: under the protection of inert gas, 3-(2, 4, 6-trimethylphenyl)-2-oxo-1-oxaspiro[4, 5]-non-3-ene-4-ol and dichloromethane are stirred and cooled to 0-5 DEG C, then triethylamine is added, fluorine ethyl chloroformate is added dropwise, after dropwise addition is completed, the reaction is continued after being raised to room temperature, and then purification is conducted, and the spiromesifen derivative is obtained; the spiromesifen derivative has higher safety for citrus, watermelon and Chinese rose and has better pest control activity than that of spiromesifen.

The present invention relates to an intermediate of monepantel and a preparation method thereof, and belongs to the field of medicine and chemical technology. The present invention provides a preparation method of a monepantel intermediate 1B, which is reacted as follows: wherein R1 is selected from benzyl or substituted benzyl, and the substituted benzyl is a benzyl arbitrarily substituted by 1 4 groups selected from the following groups on a phenyl ring: C1 4 alkyl, C1 4 alkoxy, nitro, cyano, trifluoromethyl, trifluoromethoxy; comprising the following steps: step A: a compound of formula 1A is subjected to an acylating agent and an aminating agent to obtain a compound of formula 1B; the method provided by the present invention avoids the use of ethyl chloroformate and trifluoroacetic anhydride and the generation of esterification impurities, avoids nitration and diazotization reactions, makes the preparation process of monepantel easier and simpler, and is suitable for industrial production.

The invention relates to the technical field of tail gas treatment, in particular to a carbon fiber adsorption filler for tail gas generated in ethyl chloroformate production and a preparation method thereof.The preparation method comprises the following steps that iron phthalocyanine is taken and added into N, N-dimethylformamide, the mixture is stirred to be uniform, under nitrogen protection, surface modified carbon fibers are immersed, heating and heat preservation reaction are conducted, washing is conducted after the reaction is finished, and the carbon fiber adsorption filler for tail gas generated in ethyl chloroformate production is obtained; and drying to constant weight, and performing high-temperature activation treatment in a muffle furnace to obtain the carbon fiber adsorption filler for the tail gas in ethyl chloroformate production. The carbon fiber adsorption filler prepared by the invention has relatively high decomposition efficiency on phosgene in tail gas in ethyl chloroformate production.

The present invention provides a method for synthesizing spirotetramat, and relates to the technical field of pesticide chemical industry. The present invention mixes SN-1 intermediate, ethyl chloroformate, inorganic acid binding agent, amine catalyst and organic solvent, performs condensation reaction, and obtains spirotetramat; The inorganic acid binding agent includes at least one of carbonate, bicarbonate and hydroxide. The present invention uses at least one of carbonate, bicarbonate and hydroxide as inorganic acid binding agent, which has no irritating smell, low cost and can be dissolved in water, and does not produce organic alkali wastewater in the synthesis process of spirotetramat, greatly reducing the cost of organic wastewater treatment, and does not produce nitrogen-containing waste gas in the subsequent purification process, and the synthesis method is environmentally friendly. Moreover, the synthesis method provided by the present invention has high product yield, high purity, light product appearance color, high product quality, short synthesis route, short production cycle, high production efficiency, simple operation, low production cost, and is suitable for industrial production.

The invention relates to the technical field of spraying systems, in particular to an alkali liquor spraying system for producing ethyl chloroformate, which comprises the following steps: S1, adding tetramethylammonium hydroxide into water, heating to room temperature, stirring until the tetramethylammonium hydroxide is completely dissolved, adding modified sodium metasilicate, ethylenediamine tetraacetic acid disodium salt and sodium lignin sulfonate, controlling the temperature, stirring, and filtering to obtain a solution A; alkali liquor is obtained; s2, turning on a power supply of the control system, ensuring normal operation of the control system, setting operation parameters of a spraying system, starting an alkali liquor pump, pumping alkali liquor out of the storage tank, conveying the alkali liquor to a spraying head through a pipeline, adjusting the output flow of the pump, starting intermittent and uniform spraying of the alkali liquor, and enabling sprayed waste liquor to flow into a precipitation tank through a pipeline for post-treatment. According to the alkali liquor spraying system, the purification efficiency of acid gas, heavy metal ions and organic pollutants in waste gas can be remarkably improved.

The application discloses a preparation method of cardolan, and comprises the following steps: 1) adding 2-hydroxybenzamide and an inorganic base into water as a solvent to react; and 2) adding ethyl chloroformate, heating and ring closing to obtain cardolan. The application has the advantages that water is used as the solvent, which is beneficial to an environment-friendly reaction, ethyl chloroformate is added at room temperature, and the operation is simple and the energy consumption is low; meanwhile, the product with high quality and high yield is prepared in one step.

The application provides a new synthesis method of esacioxin intermediate. The method comprises the following steps: (1) reacting raw material 2-(trifluoromethyl) phenylacetic acid with ethyl chloroformate or isobutyl chloroformate in an inert solvent in the presence of a base to generate a mixed anhydride, and then reacting with ammonia to obtain a corresponding amide compound formula II; (2) preparing an isonitrile compound formula III through a dehydration reaction of the amide compound formula II obtained in the step (1) in the presence of a dehydrating agent and an acid binding agent; (3) cyclizing the isonitrile compound formula III obtained in the step (2) with 2-butynoic acid ethyl ester in the presence of a base and a metal catalyst to form a pyrrole ring compound formula IV; and the reaction formula is shown in the following formula: compared with the prior art, the technical scheme of the application has the advantages of high yield, simple post-treatment, low cost and easy industrialization.

The application belongs to the technical field of medicine synthesis, and particularly relates to a synthesis method of empagliflozin. The application uses cobalt dibromide complex and zinc powder as a catalyst, and realizes carbon-carbon bond construction of aryl bromide by using ethyl chloroformate as a bridge, so as to realize synthesis of an important intermediate II of empagliflozin. The intermediate is further reduced and deprotected to obtain empagliflozin. The process can solve the use of n-butyl lithium, the whole synthesis route is short, operation is simple, and the process is more suitable for industrial mass production.

This invention discloses a method for synthesizing and applying propyl 4-{[(1R)-1-phenylethyl]amino}-5-(methoxycarbonyl)-1,2,3,6-tetrahydropyridine-1-carboxylate, belonging to the field of pharmaceutical preparation technology. Specifically, the method involves: removing the tert-butyloxycarbonyl group from 1-tert-butyl 4-oxopiperidinium-1,3-dicarboxylate methyl ester under oxaloyl chloride conditions; reacting the obtained intermediate with ethyl chloroformate in dichloromethane solvent to prepare compound 2; and then reacting compound 2 with the amino group of (R)-(+)-1-phenylethylamine via a nucleophilic substitution reaction to prepare propyl 4-{[(1R)-1-phenylethyl]amino}-5-(methoxycarbonyl)-1,2,3,6-tetrahydropyridine-1-carboxylate. The compound exhibits good lipid-lowering activity and can be used as a potential lipid-lowering drug for the treatment of related diseases. Furthermore, the synthesis method is simple, efficient, and low-cost, and the prepared product has high purity, making it easy to achieve large-scale industrial production.

The present application relates to tail gas treatment technical field, especially to a kind of ethyl chloroformate production containing light tail gas absorption treatment process, comprising the following steps: S1, pretreatment: collecting each workshop tail gas is filtered into bag filter, and pretreatment tail gas is obtained;S2, falling film absorption treatment: pretreatment tail gas temperature is reduced to ≤40 ℃, then it is imported into falling film absorption tower, and packing layer is equipped with the light gas absorbent with concentration of 20-30%, and falling film absorption tail gas is obtained;S3, three-stage destruction tower treatment: falling film absorption tail gas is imported into three-stage destruction tower in series, and by-product salt solution and destruction tail gas are obtained, and the salt generated is collected to storage tank, and destruction tail gas is discharged after detection reaches standard.The light gas absorbent prepared by the present application shows higher light gas and ethyl chloroformate decomposition efficiency in the absorption treatment of ethyl chloroformate production containing light tail gas.

The application belongs to the technical field of herbicides, and provides a preparation method of the herbicide cycloxaprid, which comprises the following steps: 1, mixing and stirring monocyanamide and ethyl chloroformate, cooling to 0-2 DEG C, adding liquid alkali dropwise, controlling pH and temperature, and carrying out incubation reaction to obtain a product GH520-1; 2, adding dimethyl sulfate and benzyl triethylammonium chloride to the product GH520-1, carrying out warming reaction, and after the reaction is completed, standing and layering to obtain a product GH520-2; 3, adding dimethylamine hydrochloride and liquid alkali to the product GH520-2, supplementing toluene, carrying out warming reaction, cooling to room temperature, standing and layering to obtain a product GH520-3; 4, dissolving the product GH520-3 in toluene, adding cyclohexyl isocyanate, and controlling the reaction temperature to obtain a product GH520-4; and 5, adding sodium methoxide and dimethylamine aqueous solution to the product GH520-4, controlling the reaction temperature, and obtaining a product GH520.

The invention discloses an ethyl chloroformate synthesis waste gas treatment method, and belongs to the technical field of ethyl chloroformate synthesis waste gas treatment.The ethyl chloroformate synthesis waste gas treatment method comprises the following steps that S1, waste gas is guided into 2-3 condensers connected in series, and the waste gas is condensed, liquefied, separated and recycled; s2, introducing the uncondensed waste gas into an adsorption tower for adsorption treatment; s3, the waste gas subjected to adsorption treatment enters a catalytic hydrolysis tower to be subjected to catalytic oxidation treatment; s4, finally, the waste gas enters an alkali liquor destroying tower to be treated before being emptied, and the standard waste gas can be discharged at high altitude. According to the ethyl chloroformate synthesis waste gas treatment method, a condensation liquefaction method, an adsorption method, a catalytic oxidation method and alkali liquor treatment are combined and cooperate with one another, recycling of ethyl chloroformate synthesis waste gas can be improved, and the waste gas purification effect can also be improved.

The invention relates to the technical field of tail gas treatment, in particular to an ethyl chloroformate production light-containing tail gas absorption treatment process which comprises the following steps: S1, pretreatment: collecting tail gas of each workshop, and introducing the tail gas into a bag-type dust collector for filtering to obtain pretreated tail gas; s2, falling film absorption treatment: reducing the temperature of the pretreated tail gas to be less than or equal to 40 DEG C, introducing the pretreated tail gas into a falling film absorption tower, and filling a filler layer with a phosgene absorbent with the concentration of 20-30% to obtain tail gas after falling film absorption; and S3, third-stage destroying tower treatment: introducing the tail gas subjected to falling film absorption into a third-stage series-connection destroying tower to obtain a byproduct salt solution and destroyed tail gas, collecting generated salt into a storage tank, and discharging the destroyed tail gas after the tail gas is detected to reach the standard. The phosgene absorbent prepared by the preparation method disclosed by the invention shows relatively high phosgene and ethyl chloroformate decomposition efficiency in absorption treatment of light-containing tail gas produced by ethyl chloroformate.

The invention belongs to the technical field of medicine synthesis, and particularly relates to a method for synthesizing chlorzoxazone. According to the method, (5-chloro-2-hydroxyphenyl) tert-butyl carbamate is used as a starting material, phenolic hydroxyl of the tert-butyl carbamate is activated by methanesulfonic anhydride and then is cyclized to prepare the target product chlorzoxazone, an oxazolidinone ring is constructed by Boc carbonyl oxygen replacement reaction, use of carbonylation reagents with high toxicity, such as diphosgene, carbon tetrabromide and ethyl chloroformate, is avoided, and the method is suitable for industrial production. Meanwhile, the generation of toxic gas ammonia gas when urea participates in reaction in the prior art can be avoided, and the method is more suitable for industrial large-scale production.

The application discloses a coumarin derivative containing an amide bond and a preparation method and application thereof, and has the characteristics that the specific compound structure of the coumarin derivative is 4-methyl-7-acetylamino coumarin, and the preparation method steps are as follows: 1) 3-hydroxyphenyl ethyl carbamate is prepared by amidation reaction of m-aminophenol and ethyl chloroformate; 2) 4-methyl-7-ethoxycarbonylamino coumarin is prepared by esterification reaction of 3-hydroxyphenyl ethyl carbamate and ethyl acetoacetate; 3) 4-methyl-7-aminocoumarin is prepared by esterolysis reaction of 4-methyl-7-ethoxycarbonylamino coumarin and a mixture of glacial acetic acid and concentrated sulfuric acid; and 4) 4-methyl-7-acetylamino coumarin is prepared by esterification reaction of 4-methyl-7-aminocoumarin, pyridine and acetic anhydride, and the advantages are that the compound has good antiviral and killing effects on white spot syndrome virus, the synthesis method is simple, and the conversion rate is high.

The application discloses a preparation method of L-2,4-diaminobutyric acid dihydrochloride, which comprises the following steps: (1) taking L-homoserine as a starting material, and reacting with concentrated hydrochloric acid in the presence of a zinc chloride / ferrous chloride synergistic catalyst to prepare L-2-amino-4-chlorobutyric acid hydrochloride; (2) after neutralization, acylation reaction is carried out with ethyl chloroformate to generate N-ethoxycarbonyl-L-4-chlorobutyramic acid; (3) esterification is carried out with ethanol to obtain N-ethoxycarbonyl-L-4-chlorobutyramic acid ethyl ester; (4) under the catalysis of sodium iodide, nucleophilic substitution reaction is carried out with phthalimide potassium salt, a key intermediate is purified by dropping water to reduce temperature and crystallize, and L-2-[(ethoxycarbonyl)amino]-4-phthalimidobutyric acid ethyl ester is obtained; and (5) finally, hydrolysis and deprotection are carried out, concentration and crystallization are carried out to obtain L-2,4-diaminobutyric acid dihydrochloride. The application has the advantages of mild reaction condition, simple operation, high total yield and the like, and is suitable for large-scale industrial production.

The invention relates to the technical field of pentanediol extraction and purification, in particular to a pentanediol supercritical fluid extraction and purification process which comprises the following specific steps: putting a modified raw material into an extraction kettle, injecting an ethane-methanol mixture, and fully reacting; supercritical ethane dissolved with pentanediol enters a first-stage separation kettle from the extraction kettle, and most of gaseous ethane and a mixture containing pentanediol are separated out; transferring the pentanediol-containing mixture subjected to primary separation and acetone into a secondary separation kettle, after separation is finished, reducing the pressure of the separation kettle, separating the pentanediol solution from the separation kettle, cooling to reach a supersaturated state, and separating out pentanediol crystals; and washing the crystal with cold deionized water, and carrying out vacuum drying to obtain pentanediol. The ethyl chloroformate and the impurities are subjected to esterification reaction, so that the physical and chemical properties of the impurities are different from those of pentanediol, and the pentanediol is separated more efficiently due to different solubility in the subsequent extraction process.

The invention relates to the technical field of tail gas treatment, in particular to a tail gas trapping treatment system applied to ethyl chloroformate synthesis, which comprises the following steps: S1, pretreating tail gas by a condenser; s2, performing falling film absorption to obtain concentrated hydrochloric acid and tail gas after falling film absorption; s3, performing catalytic decomposition on phosgene to obtain diluted hydrochloric acid and tail gas subjected to catalytic decomposition; and S4, carrying out two-stage series alkali washing, carrying out circulating spraying by using dilute alkali liquor, and discharging through an induced draft fan. Low-boiling-point substances such as ethanol and ethyl chloroformate in the tail gas are recovered through pretreatment of the condenser, and condensate is returned to a production system for cyclic utilization, so that the waste of raw materials is reduced, and the production cost is reduced. The hydrogen chloride is efficiently absorbed and converted into concentrated hydrochloric acid and diluted hydrochloric acid for recycling or selling in the next working section, so that the reutilization of resources is realized, and the emission of harmful gases is reduced.