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41results about How to "Excellent yield" patented technology

Catalyzed coupling reactions of aryl halides with silanes

A process for conducting coupling reactions of aryl halides with unsaturated silanes is described. The processes use N-heterocyclic carbenes as ancillary ligands in these coupling reactions. A coupling of an aryl halide with an unsaturated silane can be carried out by mixing, in a liquid medium, at least one strong base; at least one aryl halide or aryl pseudohalide in which all substituents are other than silyl groups, wherein the aryl halide has, directly bonded to the aromatic ring(s), at least one chlorine atom, bromine atom, or iodine atom; at least one silane wherein the silicon atom is quaternary, wherein one group bound to the silicon atom is unsaturated at the alpha or beta position, and wherein each of the remaining groups bound to the silicon atom is a saturated hydrocarbyl or a saturated hydrocarbyloxy group; at least one nickel, palladium, or platinum compound, wherein the formal oxidation state of the metal is zero or two; and at least one N-heterocyclic carbene. One preferred type of N-heterocyclic carbene is an imidazoline-2-ylidene of the formulawherein R1 and R2 are each, independently, alkyl or aryl groups having at least 3 carbon atoms, R3 and R4 are each, independently, a hydrogen atom, a halogen atom, or a hydrocarbyl group.
Owner:UNIV OF NEW ORLEANS RES TECH FOUND

Preparation method for 4-chlorophenylhydrazine hydrochloride

InactiveCN103910650AEliminates the problem of easy agglomeration and difficult operation of feedingEasy dischargeHydrazine preparationSolubilityHydrogen Sulfate
A provided preparation method for 4-chlorophenylhydrazine hydrochloride comprises the following steps: 1) under an acidic condition, at 5-10 DEG C, dropwise adding a sodium nitrite aqueous solution with a concentration of 20% into 4-chloroaniline to perform a diazo reaction and to generate a diazo salt; 2) under a room temperature condition, dropwise adding an ammonium sulfite aqueous solution into a solution of the diazo salt obtained in the step 1, heating to 50-60 DEG C and keeping the temperature for 3-4 h; and 3) at 50-70 DEG C, dropwise adding a hydrochloric acid solution with a concentration of 20% into the solution obtained in the step 2, keeping the temperature for 1-2 h, reducing the temperature, filtering, washing, discharging the material, and drying to obtain a finished product. The beneficial effects comprise that by using ammonium sulfite aqueous solution as a reducing agent in the reduction reaction, the problems are solved that sodium sulfite solid is easy to cake during material charging in a conventional technology and material charging is not easy to operate; ammonium chloride and ammonium hydrogen sulfate which are generated in the acidification reaction have high solubility in water, and crystallization precipitation is late, thereby facilitating performing of the acidification reaction in the solution and reducing side reactions; and the product crystallizes loosely, is good in fluidity, easy for material discharging and washing, and product quality and yield are both better than conventional production levels.
Owner:TIANJIN QIDONG CHEM PLANT

Method for producing 5-nitroguaiacol sodium salt by using micro-channel reaction device

The invention discloses a method for continuously producing 5-nitroguaiacol sodium salt by using a micro-channel reaction device. The method comprises the following steps of: (1) pumping a guaiacol-acetic anhydride solution containing an acidic catalyst into a micro-channel reactor I for reaction to obtain an acetyl guaiacol solution; (2) respectively pumping the cooled acetyl guaiacol solution and a nitric acid-acetic acid mixed solution into a micro-channel reactor II simultaneously for reaction to obtain a 5-nitroacetyl guaiacol solution; (3) cooling the 5-nitroacetyl guaiacol solution, pouring the 5-nitroacetyl guaiacol solution into water for crystallization, performing filtering, and collecting filter residue to obtain a 5-nitroacetyl guaiacol wet product; and (4) adding the 5-nitroacetyl guaiacol wet product into a sodium hydroxide solution, carrying out heating reaction, at the end of the reaction, conducting cooling, crystallizing and filtering, collecting the filter residue,and performing drying to obtain the 5-nitroguaiacol sodium salt. According to the method, the utilization rate of acetic anhydride reaches 95% or above, the nitration reaction yield is increased to 90% or above, and the three-step yield of 5-nitroguaiacol sodium salt is 80% or above.
Owner:郑州郑氏化工产品有限公司

Method for reducing early bolting of Chinese angelica

The invention discloses a method for reducing the early bolting of Chinese angelica. The method includes selecting black soil and heilu soil with excellent conditions to perform sowing, the period ofcrop rotation being more than 3 years, performing shallow ploughing for one time before sowing, applying well-rotted farmyard manure, urea, diammonium phosphate and potassium sulfate before the soil is turned up, and killing pests; then transplanting seedlings, and selecting soybean seeds to perform dibbling; performing sterilization on the seedlings before transplanting, and performing air-dryingwhile performing soaking; performing transplanting in mid-to-late March, performing covering with wide films to perform dibbling, and planting one row of soybeans and three rows of Chinese angelica after mulching; during the transplanting of the Chinese angelica, respectively planting one seedling on the two sides of each hole, the distances of the terminal bud on the heads of the seedlings of the Chinese angelica from the mulching films being 2-3 cm, performing compacting with fine soil, and tightly sealing broken gaps; and during the dibbling of the soybeans, putting 2 soybean seeds in eachhole, performing compacting with the fine soil, and tightly sealing the broken gaps. The bolting rates after the intercropping of the Chinese angelica and the soybeans are lower than that of the monoculture of the Chinese angelica; the influence of different intercropping ratios on the bolting rates is different; when the Chinese angelica is intercropped with the soybeans in a ratio of 3:1, the bolting rate of the Chinese angelica is the lowest, which is only 26.06%; and the annual growth rate of the Chinese angelica can reach up to 66%.
Owner:CHINA ACAD OF SCI NORTHWEST HIGHLAND BIOLOGY INST
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