- Synthesis method for preparing 3,5-dichloro-2-pentanone from methyl acetoacetate
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The invention discloses a synthesis method for preparing 3,5-dichloro-2-pentanone from methyl acetoacetate. The method comprises the following steps: S1: reactor preparation: preparing two reactors, namely a first reactor and a second reactor; S2, reactor cleaning: putting the first reactor and the second reactor into clear water for cleaning, flushing the first reactor and the second reactor after cleaning is completed, and drying the first reactor and the second reactor after flushing is completed; and S3, hydrolysis for salt formation: adding methyl acetoacetate into the first reactor, dropwise adding 30% caustic soda liquid under cooling of circulating water, and continuing to conducting a reaction for 6 hours after dropwise adding so as to obtain a hydrolyzed material. According to the synthesis method for preparing 3,5-dichloro-2-pentanone from methyl acetoacetate, working steps are rigorous, flammable and explosive materials are prevented from being used, safety is improved, reaction operations are reduced, reaction efficiency is improved, and cost is effectively reduced.
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Paragraph 0023-0024; 0029-0032; 0037-0040; 0045-0048; 0053
(2020/10/30)
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- Synthesis method of 3,5-dihalogenated-2-pentanone
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The invention discloses a synthetic method of 3,5-dihalogenated-2-pentanone, and belongs to the technical field of organic chemistry. According to the method, acetoacetate is taken as a raw material,and cyclopropanation, ring-opening halogenation and hydrolysis decarboxylation reactions are carried out successively so as to obtain 3,5-dihalogenated-2-pentanone. The method has the advantages of simple and accessible raw materials, high atom utilization ratio in the halogenation step and fewer wastes. The reaction conditions of all steps are simple, purification is not needed in the process, continuous feeding can be achieved, cyclic application of the cyclopropanation catalyst can be achieved, and potential industrial amplification prospects are achieved.
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Paragraph 0007; 0020; 0024-0025; 0049-0050
(2020/06/16)
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- A process for preparing 3, 5 - dichloro -2 - pentanone continuous flow method (by machine translation)
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The invention relates to a process for preparing 3, 5 - dichloro - 2 - pentanone continuous-flow method, in continuous flow reaction device, through the metering of the reservoir tanks will be α - acetyl - α - chloro - γ - butyrolactone and hydrochloric acid is pumped into the reaction in the device, in the 50 - 90 °C under continuous reaction to obtain 3, 5 - dichloro - 2 - pentanone. The technical scheme of the present invention with compared with traditional kettle reaction method, avoiding the product and acid long-term contact, product with short residence time, does not produce by-products and tar, with operation and after treatment is simple, the product yield and advantage of having high purity. (by machine translation)
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Paragraph 0008; 0024-0041
(2019/11/04)
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- 3,5-dichloro-2-pentanone preparation method
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The invention relates to the field of fine chemicals, and discloses a 3,5-dichloro-2-pentanone preparation method, which comprises: making alpha-acetyl-gamma-butyrolactone contact sulfonyl chloride ina solvent-free system to carry out a chlorination reaction, mixing the material obtained by the chlorination reaction with water, adding hydrochloric acid to the obtained mixture in a dropwise manner, and carrying out a ring-opening reaction. According to the present invention, the solvent-free one-pot reaction is achieved by using the cheap industrial chemicals as the raw materials, such that the process operation is simplified, the three-waste and the production cost are reduced, and the pollution caused by the use of the metal catalyst is avoided.
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Paragraph 0027-0050
(2019/02/10)
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- Synthetic method of midbody 3,5-dichloro-2-pentanone
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The invention discloses a synthetic method of midoby 3,5-dichloro-2-pentanone. The synthetic method adopts alpha-acetyl-gamma-butyrolactone, anhydrous potassium carbonate, alpha-acetyl-alpha-chloro-gamma-butyrolactone, hydrochloric acid, glacial acetic acid, Cu2O, benzidine and anhydrous THF as main raw materials, adopts alpha-acetyl-gamma-butyrolactone to be converted to the corresponding enol structure under the catalytic effect of the lewis acid-sulfonyl chloride, the chloride ions attach the alpha site of carbonyl, then protons are transferred, hydrogen protons are removed from a hydrogengroup, and then the hydrogen protons are re-arranged and converted to the carbonyl with more stable structure. When the acetic acid is used as a solvent and has certain solubility for an organic phaseand the hydrochloric acid, the reaction is easier, the reaction yield is greatly increased under the effect of a catalyst, the production process of prothioconazole is shortened, and the energy consumption is reduced.
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Paragraph 0007; 0021; 0022; 0023; 0024; 0027
(2018/11/03)
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- A 3, 5 - dichloro - 2 - pentanone synthetic method (by machine translation)
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The invention discloses a 3, 5 - dichloro - 2 - pentanone synthesis method, the α - acetyl - γ - butyrolactone to sulfonyl chlorine chloro- by heat after the open loop in the hydrochloric acid solution, decarboxylation, chloro, to obtain the crude product, is distilled under reduced pressure to obtain the high pure 3, 5 - dichloro - 2 - pentanone. The method used at the same time phase transfer catalyst and a Lewis acid catalyst, to avoid black caused by tar, the reaction speed is accelerated, improves the yield of primary alcohol chloro, this line is simple in operation, easy processing, high yield, is suitable for industrial production. (by machine translation)
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Paragraph 0014; 0016; 0017; 0019; 0020-0039
(2017/08/28)
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- A 3, 5 - dichloro - 2 - pentanone synthesis process (by machine translation)
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The invention discloses a 3, 5 - dichloro - 2 - pentanone synthesis process, the process uses water as solvent, α - acetyl - γ - butyrolactone in the double-layer glass reactor in the judgement of the sulfonyl chlorine chloro-, ring opening hydrolysis, decarboxylation, re-chloro continuous reaction, high purity is obtained 3, 5 - dichloro - 2 - pentanone. The method adopts the stage temperature control reaction, compared with the traditional technology does not need to add any catalyst, can make the reaction totally, safety and environmental protection, low cost, high yield reaction at the same time, industrialized the operability is strong, and has good application prospect. (by machine translation)
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Paragraph 0032; 0033; 0035; 0037; 0039; 0041; 0043; 0045
(2018/04/02)
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- Synthetic method for preparing 3,5-dichloro-2-pentanone with ethyl acetoacetate
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The invention provides a synthetic method for preparing 3,5-dichloro-2-pentanone with ethyl acetoacetate. The method comprises the following steps that ethyl acetoacetate, sodium ethoxide, ethyl alcohol and 1,2-dichloroethane serve as raw materials, a chlorination reaction is conducted, and after a sulfonyl chloride chlorination reaction and a diluted acid hydrolysis decarboxylation reaction are conducted, 3,5-dichloro-2-pentanone is obtained through atmospheric distillation. Accordingly, ethyl acetoacetate, 1,2-dichloroethane, sulfonyl chloride, diluted acid and the like serve as the raw materials, the raw materials are low in toxicity, low in price and easy to obtain, active metal sodium and an inflammable and explosive material ethylene oxide are not used, the potential safety hazard of industrial scale -up production is lowered, the process is simple, and the product purity and yield are high.
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Paragraph 0035; 0036; 0037; 0040; 0043; 0046; 0049; 0052
(2018/04/02)
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- Synthetic method of 3, 5-dichloro-2-pentanone
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The invention discloses a synthetic method of 3, 5-dichloro-2-pentanone. Under the action of salt and a phase transfer catalyst, alpha-chloro-alpha'-acetyl-gamma-butyrolactone, which is used as a raw material, reacts with hydrochloric acid; and then, 3, 5-dichloro-2-pentanone is synthesized through a continuous steam distillation method. According to the characteristic of great boiling point difference between the raw material and the product, the technical scheme of reacting while separating is adopted. Therefore, purity of the product is raised, yield is greatly increased, and the hydrochloric acid solution in the reaction can be recycled. By adding the phase transfer catalyst, reaction speed of the raw material can be raised, and accumulation of the raw material in the reaction system is reduced. By adding salt, reaction distillation temperature can be increased, product separation speed is accelerated, and retention time of the raw material and the product in the reaction system is shortened. Thus, side reaction is minimized, and selectivity is enhanced.
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Paragraph 0014
(2017/02/17)
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- 3-(2-Haloalkyl)-1,4-oxathiins and 2-(2-haloalkyl)-1,4-dithiins, and treatment of leukemia and tumors therewith
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Novel 3-(2-haloalkyl)-1,4-oxathiins or 2-(2-haloalkyl)-1,4-dithiins, useful for regressing or inhibiting the growth of leukemia and tumors in mammals. The compounds have the formula.: STR1 wherein R1 is an alkyl group containing up to 4 carbon atoms, cyclohexyl or phenyl; R2 is hydrogen or ethyl; R3 and R4 are each hydrogen, methyl or ethyl, and when either R3 and R4 is methyl or ethyl, the other is hydrogen; X is halogen; and Y is oxygen or sulfur and when Y is sulfur, R3 and R4 are both hydrogen. and pharmaceutical compositions comprising said compounds in admixture with a pharmaceutically acceptable substantially non-toxic carrier.
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- Synthesis of Cyclopropane Derivatives from Electron-deficient Olefins and Dichloromethane via Copper(I) Catalysed Photochemical Addition followed by an Electroreductive Dehalogenation Reaction
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The CuCl-catalysed photochemical reaction of electron-deficient olefins with dichloromethane gave 1,3-dichloro compounds, which then afforded cyclopropane derivatives by electrochemical reduction.
- Mitani, Michiharu,Yamamoto, Yasuo,Koyama, Kikuhiko
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p. 1446 - 1447
(2007/10/02)
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