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104 results about "Acetone cyanohydrin" patented technology

Acetone cyanohydrin (ACH) is an organic compound used in the production of methyl methacrylate, the monomer of the transparent plastic polymethyl methacrylate (PMMA), also known as acrylic. It liberates hydrogen cyanide easily, so it is used as a source of such. For this reason, this cyanohydrin is also highly toxic.

Preparation method of alpha-hydroxypyridine by acetone cyanohydrin

The invention relates to a preparation method of alpha-hydroxypyridine by acetone cyanohydrin, and relates to a preparation method of alpha-hydroxypyridine. The method solves the problems that the existing preparation method of the alpha-hydroxypyridine is low in yield, big in catalyst toxicity, high in price, complex in preparation method, and long in reaction time. The method includes steps of firstly, immersing cation exchange resin in 20% by weight of organic amine methanol solution; filtering, washing and drying the solution to obtain catalyst; secondly, dissolving acetone cyanohydrin and aromatic aldehyde in the methanol, and adding catalyst to react and obtain the alpha-hydroxypyridine; filtering the catalyst, depressurizing and evaporating methanol and acetone; extracting and separating the methanol and acetone; after drying, rotationally evaporating and removing ethyl acetate to obtain the alpha-hydroxypyridine. The method applies the simple and easily-prepared catalyst, and the reaction can be completed under room temperature condition; the reaction yield is up to over 95%. The operation method is simple and easy to practice, and the catalyst can be repeatedly used and is more applicable to the industrial production. The preparation method is applied to prepare alpha-hydroxypyridine.
Owner:HARBIN UNIV OF SCI & TECH

Synthetic process of herbicide tembotrione

The invention discloses a synthetic process of herbicide tembotrione. The synthetic process comprises the following steps: step 1) adding methyl 2-chloro-3-methyl-4-methylsulfonylbenzoate, a solvent,a catalyst and hydrobromic acid at the first, then dropwise adding hydrogen peroxide, washing with water, concentrating and recrystallizing after reaction to obtain bromine methyl 2-chloro-3-bromomethyl-4-methylsulfonylbenzoate; step 2) enabling the bromide, an alkali 1, the catalyst, the solvent and 2,2,2-trifluoroethanol to react, filtering, washing with water and concentrating after reaction; adding an alkali 2 and water to react, acidifying, filtering, washing and drying to obtain an etherate 2-chloro-3-(2,2,2-trifluoroethoxy)methyl-4-methanesulfonylbenzoic acid; and step 3) removing the solvent after reacting the etherate, the catalyst, thionyl chloride and the solvent; adding 1,3-cyclohexanedione and the solvent, dropwise adding triethylamine; adding acetone cyanohydrin after reaction, washing with water, layering, removing the solvent from an oil layer, adding the solvent for recrystallization, filtering and drying to obtain a beige solid, namely tembotrione. The synthetic process provided by the invention increases the yield of an intermediate, is more environmentally-friendly and safer, and reduces production costs.
Owner:ZHEJIANG ZHONGSHAN CHEM IND GRP

Method for preparing alpha-aminoisobutyric acid

The invention aims at the field of chemical industry and relates to a method for preparing alpha-aminoisobutyric acid. The method comprises the step of enabling acetone cyanohydrin and ammonium carbonate to be subjected to pressurized and heated reaction in an aqueous medium, thereby synthesizing alpha-aminoisobutyric acid, wherein ammonium carbonate can be replaced with ammonium bicarbonate or ammonia and carbon dioxide. The invention further relates to preparation using an alpha-aminoisobutyric acid production device, wherein a gas stripping device is especially used for recovering carbon dioxide and ammonia gas which are generated during synthesis reaction and are recycled for the synthesis of alpha-aminoisobutyric acid. According to the method disclosed by the invention, the yield is high, the purity of a product is high, and the equipment investment is small; in a whole process, carbon dioxide and ammonia are hardly consumed, no byproduct inorganic salt is produced, and inorganic base is not consumed, so that a very positive effect on the full and comprehensive utilization of resources and environmental protection is exerted; recovered carbon dioxide and ammonia and crystallized mother liquor are sufficiently utilized, so that the problem of pollution to environment caused by waste gases, waste water and waste residues can be excellently solved, and the environmental-friendly and clean production is really achieved.
Owner:CHONGQING UNISPLENDOUR INT CHEM

Method of preparing azodiisobutyronitrile

The invention relates to a method of preparing azodiisobutyronitrile. The method comprises the following steps: a, carrying out a reaction on acetone cyanohydrin and hydrazine hydrate to generate diisobutyronitrile hydrazine; and b, introducing chlorine to diisobutyronitrile hydrazine to react to generate azodiisobutyronitrile, wherein hydrazine hydrate used in the step a is prepared by a urea method. The hydrazine hydrate is specifically prepared by the following steps: (1) introducing chlorine to a caustic soda solution to generate sodium hypochlorite; (2) adding solid urea to prepare a urea saturated solution and carrying out a reaction with sodium hypochlorite to obtain a coarse solution containing hydrazine hydrate; and (3) freezing and crystallizing the coarse solution containing hydrazine hydrate to separate sodium carbonate decahydrate so as to obtain a refined solution of hydrazine hydrate, adding a neutralizer to neutralize the pH to 2-3, removing sodium hydroxide and sodium carbonate in the solution, and then adding the refined solution of hydrazine hydrate to reversely neutralize to PH to 10-10.5. According to the method provided by the invention, the purification process of the hydrazine hydrate solution is canceled and the production procedure is simplified, so that the production cost is greatly lowered.
Owner:唐山晨虹实业有限公司

Method for producing 5,5-dimethyl hydantoin

The invention discloses a method for producing 5,5-dimethyl hydantoin which is prepared from the following substances in parts by weight according to the steps as follows: adding water to ammonium bicarbonate and acetone cyanohydrin, stirring until the ammonium bicarbonate and the acetone cyanohydrin are fully dissolved, and sealing up while heating up to 10 DEG C; introducing ammonia to the mixture, heating slowly to 50-65 DEG C, stirring, heating up to 75-85 DEG C after keeping temperature constant for 1-2 hours, introducing air for 30-50 minutes, and filtering after cooling to a room temperature, thus obtaining crude dimethyl hydantoin and a mother liquid; and putting the crude dimethyl hydantoin into the mixture of water and the mother liquid while stirring, adding active carbon after heating up to 80-98 DEG C, decolouring, removing the active carbon by filtration, recooling, crystallizing, filtering centrifugally, and drying, thus obtaining the finished product of dimethyl hydantoin. The method has the advantages of simple technological reaction, low reaction temperature, short reaction time, less side reaction and high yield reaching 85%, and is easy to control; the raw material of ammonium bicarbonate applicable to the method belongs to chemical fertilizers, and is easy to obtain; and the filtrate produced by the technology can be used repeatedly, and no three wastes are discharged.
Owner:祝莉宁

Preparation and purification method of clean methacrylamide

The invention discloses a preparation and purification method of clean methacrylamide. The preparation and purification method disclosed by the invention comprises the following steps: taking acetone cyanohydrin as a main raw material, generating methacrylamide sulfate by hydrolysis with concentrated sulfuric acid, dehydration and other actions, neutralizing the methacrylamide sulfate with ammonia or ammonia water, then supplementing a certain amount of water to dissolve generated ammonium sulfate, getting a methacrylamide semi-finished product, indiscriminately using part of mother liquor after neutralization in a circulating manner, and performing re-crystallization and purification on the methacrylamide semi-finished product to get a methacrylamide pure product, wherein the recrystallization mother liquor can also be indiscriminately used in the circulating manner. According to the preparation and purification method disclosed by the invention, a new process route is adopted, and the mother liquor can be used indiscriminately in the circulating manner, so that the emission of wastewater containing salts and acids is greatly reduced, the environmental pollution caused by the wastewater is avoided, the dissolution of the methacrylamide in the mother liquor is further reduced, the yield of the methacrylamide is improved, the methacrylamide with the content of above 98.5% is obtained, the content of the ammonium sulfate is within 1.5%, and the yield is above 90%.
Owner:CHONGQING UNISPLENDOUR CHEM
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