15results about "Preparation by halogen elimination" patented technology

A method for supplying deaerated water to a chemical plant, wherein the chemical plant includes a distillation column for separating a reaction effluent including water and a product. The method includes charging aerated water (water having an oxygen content greater than 50 ppbw, such as greater than 1 ppmw) to the distillation column. The aerated water in the distillation column can then be distilled to produce an oxygen-containing overhead and a bottoms fraction including deaerated water. The deaerated water in the bottoms fraction can be transported to and utilized in upstream or downstream unit operations. The reaction effluent is fed to the distillation column, converting the distillation column from an operation that separates oxygen from water to an operation that separates the product from water.

Methods for preparation of olefins, including 8- and 11-unsaturated monoenes and polyenes, via transition metathesis-based synthetic routes are described. Metathesis reactions in the methods are catalyzed by transition metal catalysts including tungsten-, molybdenum-, and ruthenium-based catalysts. The olefins include insect pheromones useful in a number of agricultural applications.

The application discloses a preparation method of a key intermediate of a montelukast sodium side chain acid, belongs to the technical field of pharmaceutical intermediates, and relates to a key intermediate of a montelukast sodium side chain acid, i.e. 1-bromomethylcyclopropylacetonitrile, which is characterized by the preparation method of the 1-bromomethylcyclopropylacetonitrile. The preparation method is as follows: taking tribromoneopentyl alcohol as a starting material, and obtaining 1-bromomethylcyclopropylacetonitrile through a cyclization reaction, an iodination reaction and a cyano substitution reaction. The 1-bromomethylcyclopropylacetonitrile is prepared by using a brand-new synthesis process, starting from tribromoneopentyl alcohol, through a cyclization reaction, an iodination reaction and a cyano substitution reaction. The method solves the blank of the preparation method of 1-bromomethylcyclopropylacetonitrile in the prior art, and also solves the defects of a long reaction theoretical cycle and a low actual yield and a large amount of impurities in the reaction of preparing 1-bromomethylcyclopropylacetonitrile by first preparing 1-hydroxymethylcyclopropylacetonitrile and then reacting phosphorus tribromide with the 1-hydroxymethylcyclopropylacetonitrile.

The present invention relates to a process for producing dimethyl ether (DME) and hydrogen (H2) from methane, comprising the steps of: a) providing a gaseous feed stream comprising methane; b) reacting said gaseous feed stream with at least one halogen reactant (X2), under reaction conditions effective to produce an effluent stream comprising methyl halide (MeX), and hydrogen halide (HX); c) separating from the effluent stream obtained in step b): (i) a methyl halide (MeX) stream; and, (ii) a hydrogen halide (HX) stream; d) reacting the methyl halide (MeX) stream separated in step c) with a solid metal oxide (MO(s)) under reaction conditions effective to produce metal halide (MX) and dimethyl ether (DME); and e) decomposing by means of electrolysis said hydrogen halide (HX) stream separated in step c) under conditions effective to produce a gaseous hydrogen (H2) stream and a stream comprising halogen reactant (X2).

The present invention provides a mechanochemical reaction method and reaction apparatus that allows for operations such as adding reagents during the reaction, removing reaction products, and adding substrates for the next reaction without removing the lid of the reaction vessel, while preventing a decrease in reaction efficiency and ensuring safety. Furthermore, it allows for checking the state inside the reaction vessel, and improves operability and workability, while shortening (accelerating) the reaction process. [Solution] A mechanochemical reaction method using a reaction apparatus A comprising a reaction vessel 11 having an opening and a lid 12 that seals the opening 13 of the reaction vessel in an openable and closable manner, wherein one or more through holes 21 are provided in the reaction vessel other than the opening and / or in the lid, communicating the inside of the reaction vessel with the outside of the reaction vessel.

Stereoselective methods of producing a stereoisomer of p-menthane-3,8-diol are disclosed, the methods comprising the steps of: hydrating the alkene group of isopulegol, or performing a ring opening reaction on verbenol and hydrogenating and deprotecting the resulting diol. Also disclosed are compositions comprising 95mol% or greater of a stereoisomer of p-menthane-3,8-diol and insect repellents, flavourings or fragrances comprising such compositions. Also disclosed are methods of reducing resistance of a target insect or tick species to a p-menthane-diol repellent.

The invention relates to a method for removing chloropropylene glycol in epichlorohydrin wastewater, which comprises the following steps: in a hydrogen atmosphere, contacting the epichlorohydrin wastewater with a hydrodechlorination catalyst to carry out catalytic hydrodechlorination reaction, so that the chloropropylene glycol in the epichlorohydrin wastewater is converted into propylene glycol; wherein the hydrodechlorination catalyst comprises an activated carbon carrier and an active metal component; the active metal component comprises Ru. According to the method provided by the invention, the chloropropylene glycol in the epichlorohydrin wastewater can be efficiently removed, a propylene glycol product with higher value is obtained, and the treatment cost of the chloropropylene glycol is reduced.

In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein is versatile polyene cyclization strategy that exploits conjugated b-ionyl derivatives. Photomediated disruption of the extended p-system within these chromophores unveils a contra-thermodynamic polyene that engages in a Heck-type cyclization to afford [4.4.1]-propellanes. The connectivity of overbred polycycles generated from this process is controlled by the position of the requisite C–Halide bond. Thus, compared to conventional biomimetic polyene cyclization, this approach allows for complete control of regiochemistry and facilitates incorporation of both electron-rich and electron-deficient (hetero)aryl groups. This strategy was successfully applied to the total synthesis of abietanes such as, for example, taxodione and salviasperanol, two isomeric abietane-type diterpenes that previously could not be prepared along the same synthetic pathway.

A method for producing a compound by using a flow micro reactor (100) includes: a step for introducing a first liquid containing a raw material compound having a fluorocarbon group into a first introduction tube (101) and introducing a second liquid containing an alkali metal cation and a radical anion of a second aromatic compound into a second introduction tube (103), to thereby obtain a first mixed liquid in a first micro mixer (107); a step for obtaining a first reaction product by causing the first mixed liquid to flow in a first tube reactor (109), and introducing an electrophile into a third introduction tube (105), to thereby obtain a second mixed liquid in a second micro mixer (111); and a step for causing the second mixed liquid to flow in a second tube reactor (113) to thereby obtain a second reaction product containing a compound which is formed by replacing, with atomic groups derived from the electrophile, one or more fluorine atoms in the fluorocarbon group in the raw material compound and which contains a fluorine atom.

Methods and systems are provided for producing high purity methanol and isobutene from a crude MTBE feed using multiple partition wall columns. The method may include purifying MTBE, dissociating MTBE to produce isobutene and methanol, purifying isobutene, and recovering / purifying methanol.

This invention discloses a method for preparing 6-bromo-6,6-difluoro-1-hexanol, belonging to the field of organic synthesis. The method uses 4-penten-1-ol as a starting material, reacting it with dibromodifluoromethane via an addition reaction to prepare 4,6-dibromo-6,6-difluoro-1-hexanol; then, a dehalogenation reaction is carried out using a second metal reagent to obtain 6-bromo-6,6-difluoro-1-hexanol. In this method, the reactants and reagents are inexpensive and readily available, the reaction steps are short, and production control is convenient; the reaction conditions are mild, ensuring high safety; the process is simple, and the product has high purity.

The invention discloses a novel cyclic dihydric alcohol as well as a preparation method and application thereof, cyclohexanone is used as a raw material, a dialdehyde monomer is obtained through electrophilic addition, and then a dihydric alcohol monomer is prepared through reduction hydrogenation. The unique advantages of the cyclohexanone structure are fully played, a new way is opened up for application of cyclohexanone, the prepared dihydric alcohol can be used as a polymeric monomer for preparing a polyurethane material, and the tensile property of the prepared polyurethane material is excellent.

The present invention concerns a method of synthesizing a iodo- or astatoarene comprising the reaction of a diaryliodonium compound with a iodide or astatide salt, respectively. The invention also relates to said iodo- or astatoarene and diaryliodonium compound as such. The invention also concerns a method of synthesizing a iodo- or astatolabelled biomolecule and / or vector using said iodo- or astatoarene.

The present invention relates to a process for producing methanol (MeOH) and hydrogen (H2) from methane, comprising the steps: a) providing a gaseous feed stream comprising methane; b) reacting said gaseous feed stream with at least one halogen reactant (X2), under reaction conditions effective to produce an effluent stream comprising methyl halide (MeX), hydrogen halide (HX); c) separating from the effluent stream obtained in step b): (i) a methyl halide (MeX) stream, optionally comprising unreacted methane; and, (ii) a hydrogen halide (HX) stream; d) reacting the methyl halide (MeX) stream separated in step c) with a solid metal hydroxide (MOH(s)) under reaction conditions effective to produce metal halide (MX) and methanol (MeOH); and, e) decomposing by means of electrolysis said hydrogen halide (HX) stream separated in step c) under conditions effective to produce a gaseous hydrogen (H2) stream and a stream comprising halogen reactant (X2).