82 results about "Nitrous acid ester" patented technology

The invention discloses a preparation method for a catalyst for synthesizing oxalic ester by gas-phase. The catalyst takes alpha-alumina as a carrier, palladium as an active component and 2 MOxes as an additive, M is magnesium, titanium, zirconium, vanadium, manganese, iron, nickel, copper, zinc, molybdenum or tungsten, and components of the catalyst (calculated by carrier mass) are: 0.01 to 0.75 percent of the palladium and 0.1 to 20 percent of MOxes. The preparation method comprises the following steps that: firstly, an additive metal salt solution is used to impregnate the carrier, and a palladium salt solution is used to impregnate the carrier to obtain the catalyst after the carrier is dried and roasted. Before the use, pure hydrogen or H2-N2 mixed gas is activated by the catalyst at a temperature of between 150 and 450 DEG C. The catalyst can be used for synthesizing oxalic ester by the carbonylation of CO and nitrous acid ester, the using reaction temperature of the catalyst is between 70 and 150 DEG C, and the reaction space velocity is between 500 and 9,000h<-1>. The catalyst has higher reaction activity and selectivity; and the catalyst has low cost.

The preparation process of 1-fluoronaphthalene includes the following steps: (1) reacting 1-naphthylamine with nitrous acid, nitrous acid ester or nitrite in acid medium to obtain diazo salt; (2) reacting the diazo salt with fluoroboric acid or its salt or fluorophosphoric acid or its salt to obtain diazo fluoroborate or diazo fluorophosphate; and (3) heating the diazo fluoroborate or diazo fluorophosphate to decompose to obtain 1-fluoronaphthalene. The process has short synthesis path, less side products, mild reaction condition, easy control, relatively low cost, great production capacity, high product purity and other advantages, and the product is used as medicine intermediate.

Diesel cycle fuel compositions are described containing at least one dianhydrohexitol compound according to the general formula 2 and/or its

derived hydrocarbyl ethers or nitric ethers compounds, where the R′ and R″ substituents are both H or one or both of R′ and R″ is alkyl, cycloalkyl or phenyl, or one or both are —NO₂. A preferred fuel composition is that containing dimethyl isosorbide (DMI) added or not of isosorbide dinitrate (ISDN) as ignition improver. The dianhydrohexitols compounds form compositions with at least one of the components selected among petroleum-derived diesel fuel, biodiesel, ethanol and water. The mixture of DMI and ISDN has excellent cetane number (IQT). Still, the oxygenated nature of the dianhydrohexitols and related compounds of the fuel compositions inhibits soot formation upon burning of the said Diesel cycle fuel compositions.

The invention relates to a method for producing oxalic ester by gas phase CO coupling, which mainly solves the problems of low selectivity of the target product oxalic ester and low conversion per pass of the raw materials in the prior art. In the method, a technical scheme is adopted as follows: CO and nitrous acid ester in mol ratio of 1-5:1 are used as raw materials; a first batch of raw material as a cooling medium passes through tubes of a first tube-type fixed bed reactor, after heat exchange, enters a second fixed bed reactor, contacts with a palladium-containing catalyst II in a catalyst bed II in the reactor for reaction to generate a reaction effluent I containing the oxalic ester; and a gas phase effluent II containing CO is obtained by gas-liquid separation of the reaction effluent I, and is uniformly mixed with a second batch of raw material containing the fresh component nitrous acid ester, and the mixture is returned into the first tube-type fixed bed reactor, contacts with a palladium-containing catalyst I in a catalyst bed I outside the tubes for reaction to generate the reaction effluent containing the oxalic ester, wherein the total mol ratio of CO to nitrous acid ester in the raw material is 1-4:1, the mol ratio of the second batch of nitrous acid ester to the first batch of nitrous acid ester material is 0.2-5:1, and at least two reactors are connected in series. By using the method, the problems can be better solved and the method can be used in the industrial production for increasing the yield of the oxalic ester.

The invention belongs to the technical field of preparation of benzyl and provides a method for preparing benzil by performing catalytic oxidation on benzoin. According to the method, oxygen or air serves as an oxidizing agent, a composite catalyst consists of two components, namely vanadium oxide and nitrous acid ester, and the benzyl is prepared by performing catalytic oxidation on the benzoin at 60 to 120 DEG C. Compared with the stoichiometric chemistry oxidation methods such as traditional chromate oxidation method, the nitric acid oxidation method and the permanganate oxidation method, the method has the following advantages: the reaction condition is mild, the catalyst is cheap and efficient, the reaction is green and environment-friendly, the conversion rate of the benzoin is high,the selectivity of the benzyl is high, and good application prospect and high practical value are achieved.

The invention relates to the preparation and application of Salvia polysaccharide and its esters. The sugar chain is sorbitol, rhamnose, and galactose linked through 1->6 (or non-reducing terminal), 1->4 and 1->3 glycosidic bond. The invention provided Salvia polysaccharide and its esters is prepared from Salvia as raw material or residues of Salvia after extracting fat-soluble effective ingredient or (and) water soluble phenolic acid by leaching with hot water, concentrating, precipitating with ethanol, deproteinizing to obtain Salvia polysaccharide, and esterizing to obtain Salvia polysaccharide ester (sulfate, phosphate ester, nitric ether and acetic ester).The invention obtained Salvia polysaccharide and its esters both have strong human immunodeficiency virus and herpes simplex virus resisting activity, has low toxicity to human cell, and can be used for preparing preparation for preventing or treating AIDS viral and herpes simplex viral infection.

The invention discloses a method for preparing amino modified graphene through fatty amine modified graphene, and belongs to the field of new materials. The method comprises the following steps that fatty amine and nitrous acid ester are firstly dissolved in a solvent separately, the temperature of a mixture of the graphene and the solvent is controlled, a small amount of acid is added into the graphene, the two reactants are added into the mixture, and reaction is carried out; and filtering and washing are carried out so as obtain the amino modified graphene. The method has the advantages ofbeing simple in technological process, mild in conditions, high in safety, low in cost, capable of improving the product stability and capable of providing the possibility for industrial production oflarge-scale preparation of the fatty amine modified graphene.

The invention relates to a method for producing oxalic ester by gas phase CO coupling, which mainly solves the technical problems of low oxygen removal rate of raw materials, low selectivity of target products and low space-time yield of the oxalic ester in the prior art. The method comprises the following steps: (a) firstly, a CO gas raw material containing oxygen and NO gas enter a deoxidizing reactor and contact with a molecular sieve catalyst, and the oxygen in the raw material reacts with the NO to generate a gas phase effluent I containing NO2, unreacted NO and CO; (b) the gas phase effluent I and nitrous acid ester enter a coupling reactor and contact with a palladium-containing catalyst to react to generate an effluent II containing the oxalic ester; and (c) the effluent II of the oxalic ester is separated to obtain the oxalic ester product and a gas phase effluent III containing nitrogen oxides, wherein the mol ratio of the NO to oxygen in the CO gas raw material containing the oxygen in the step (a) is 4-100:1. By using the technical scheme, the problems are better solved and the method can be used for the industrial production for increasing the yield of the oxalic ester.

The invention relates to the field of organic synthesis, in particular to a synthetic method of a topramezone intermediate 1,2-dimethyl-3-methylsulfanyl-benzene. The method comprises the following steps: (1) reacting 2,3-dimethylaniline or a salt thereof with sodium nitrite in an acidic environment to generate a corresponding diazonium salt; and (2) reacting the diazonium salt with a methyl mercaptide to generate the 1,2-dimethyl-3-methylsulfanyl-benzene. The synthetic method of the topramezone intermediate 1,2-dimethyl-3-methylsulfanyl-benzene provided by the invention has low costs and lessthree wastes (waste gas, waste water and industrial residue), uses the sodium nitrite to replace expensive nitrous acid ester, uses the methyl mercaptide to replace dimethyl sulfide with a strong smell, has good atom economy, avoids generation of methyl mercaptide with a smell difficult to control, and avoids the problems of solvent recovery and environmental problems in the recovery process caused by the use of a large amount of the dimethyl sulfide.

The invention discloses a preparation method for an aryl tin compound. The aryl tin compound is prepared from reaction of aromatic amine Ar-NH2, distannanes, alkyl nitrous acid ester and Lewis acid in an organic solution, wherein Ar represents a substitutional or non-substitutional benzene ring or an aromatic heterocyclic ring group, and the reaction is prominently quickened by the adopted Lewis acid. According to the invention, the preparation method enables a one-step conversion of the aromatic amine into the aryl tin compound under mild condition for the first time, and is high in reaction rate and low in reaction cost; the reaction involved in the method disclosed by the invention requires no strict water-free and oxygen-free conditions, occurs smoothly in the air and is easy to operate, and meanwhile has an excellent tolerance and universality for the functional group, therefore, the method can be widely used for the preparation of aryl tin compounds.

The invention relates to a method for preparing oxalate through CO catalytic coupling reaction. The technical problems of difficulty in temperature control and low selectivity of target product during the process of preparing oxalate through CO catalytic coupling reaction in the prior art are solved. The method comprises the following steps of: taking a mixed gas containing nitrous acid ester and CO as a raw material, and contacting the raw material with a noble metal catalyst in an upper heat-insulating catalytic bed, a heat-exchange catalytic bed and a lower heat-insulating catalytic bed in a heat-point distributed area enhanced heat-exchange combined reactor in turn, under the conditions of reaction temperature at 100-180 DEG C, volume hourly space velocity at 500-10000 per hour, reaction pressure at -0.08-1.5MPa and mole ratio of CO to nitrous acid ester being (1-5):1, thereby generating an effluent containing the oxalate by reacting. According to the technical scheme, the problem is more efficiently solved. The method is suitable for the industrial production for preparing oxalate through CO catalytic coupling.

The invention relates to a method for preparing oxalic ester by CO coupling, by which the main technical problems that in a system for preparing the oxalic ester by CO coupling in the prior art, the content of nitrous acid ester in gas components entering a cyclic compressor is high and the safety is poor are solved. The invention has the technical scheme comprising the following steps: (a) firstly, gas containing CO and nitrous acid ester enters a coupling reactor to contact with a palladium catalyst and react to generate an effluent I; (b) after gas-liquid separation of the reaction effluent I, a liquid phase reaction effluent II and a gas phase reaction effluent III are obtained, and the effluent III contacts with a C1-C9 alcoholic solution in an absorption tower to obtain a liquid phase effluent IV and a gas phase effluent V; and (c) after further gas-liquid separation is carried out on the gas phase effluent V by a condenser for removing the nitrous acid ester, a gaseous effluentVI of which the content of nitrous acid ester is less than 50ppm is obtained, and the gaseous effluent VI reenters a compressing system. The technical scheme better solves the problems and can be used for industrial production of the oxalic ester.

The invention relates to a method for producing oxalate through carbon monoxide coupling, and mainly solves the technical problem in the prior art that the target product is low in selectivity. The method adopts a mixed gas containing both nitrous acid ester and carbon monoxide as the raw material, also adopts a fluidized bed reactor, and comprises the step that under the conditions that the reaction temperature is 100-180 DEG C, the hourly space velocity is 500-10,000 hours<-1> and the reaction pressure is -0.08-1.5MPa, the raw material is in contact with a palladium-containing precious metal catalyst in which lanthanum, praseodymium or bismuth is selected as the additive, so as to react to produce oxalate, wherein a catalyst carrier is spherical aluminum oxide with the average particle diameter of 20-300 microns. By adopting the technical scheme, the problem is better solved and the method provided by the invention can be used for industrial increase production of oxalate.

The invention discloses a synthetic method and process of halogenated cyclopropane. The synthesis method and process comprise the following two steps of: (1) reacting cyclopropylamine serving as a rawmaterial with halogenated metal salt in the presence of nitrosation reagents such as nitrous acid ester to obtain 1, 1-dihalogenated cyclopropane; and (2) carrying out metallization reaction on the 1, 1dihalogenated cyclopropane and an organic metal reagent, and hydrolyzing to obtain halogenated cyclopropane. The synthesis method and process have the advantages that toxic reagents causing environmental pollution are not used, the purity and yield of the obtained product are high, and the synthesis method and process are suitable for industrial production.