- Preparation method of 4-acetoxy-2-methyl-2-butenal
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The invention discloses a preparation method of 4-acetoxy-2-methyl-2-butenal, which takes salifying and wittig reactions as a core and methanol which is cheap and easy to obtain as a reaction initial raw material. The invention provides a new reaction route, the reaction steps are simple, the reaction conditions are mild, and the product yield is high.
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Paragraph 0015; 0042; 0047-0048; 0052; 0057-0058; 0062; ...
(2021/09/04)
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- Preparation method of 1-acetoxy-4-chloro-3-methyl-2-butene
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The invention provides a preparation method of 1-acetoxy-4-chloro-3-methyl-2-butene. The preparation method comprises the following steps: carrying out a chlorohydrination reaction on isoprene and a chlorine-containing compound, carrying out an esterification reaction on a reaction product and acetic anhydride, and finally, carrying out after-treatment to obtain 1-acetoxy-4-chloro-3-methyl-2-butene. The preparation method has the advantages of mild reaction conditions, high safety, less side reactions generated in the preparation process, improvement of an overall reaction rate through usage of strong acid supported resin as a catalyst, and effective improvement of the purity and the yield of the product; and the chlorine-containing compound and the catalyst in the preparation method are convenient to recycle and reuse, so preparation cost is reduced, industrial amplification feasibility is high, and the production concept of green chemical engineering is met.
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Paragraph 0055; 0085-0092; 0096; 0097
(2021/02/06)
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- Preparation method of 1-halogenated-2-methyl-4-substituted carbonyloxy-2-butene
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The invention provides a preparation method of 1-halogenated-2-methyl-4-substituted carbonyloxy-2-butene. According to the method, 2-methyl-4-hydroxy-1-butene and an acylation reagent are subjected toan acylation reaction under the action of a catalyst to prepare 2-methyl-4-substituted carbonyloxy-1-butene, and then the 2-methyl-4-substituted carbonyloxy-1-butene and halogen are subjected to an addition reaction and an alkali elimination reaction to prepare 1-halogenated-2-methyl-4-substituted carbonyloxy-2-butene. The method has the advantages of cheap and accessible raw materials and low product cost; the process flow is simple and convenient, the reaction conditions are easy to realize, the operation is safe, simple and convenient, the wastewater yield is low, and the method is green and environment-friendly; and the method also has the advantages of stable reaction intermediate product, proper reaction activity, high reaction selectivity, few side reactions and high target productyield and purity, and is suitable for green industrial production.
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- Method for preparing 4-acetoxy-2-methyl-2-butenal
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The invention provides a method for preparing 4-acetoxy-2-methyl-2-butenal. The method comprises the following steps: esterifying isopentenol to generate isopentenol acetate; and carrying out illumination oxidation on the isopentenol acetate in the presence of a photosensitizer to generate 4-acetoxy-2-methyl-2-butenal. The method has the advantages of cheap and easily available starting raw material isopentenol, high atom economy of the process route, no use of precious metals, less three wastes, and economic and effective synthesis route.
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Paragraph 0009; 0058; 0060; 0061
(2020/04/29)
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- A process for preparing 4 - acetoxy -2 - methyl -2 - butenal new method
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The present invention provides a process for preparing 4 - acetoxy - 2 - methyl - 2 - butenal new method. Comprises the following steps: 1, fed with methanol reaction to generate acetal thing (I); 2, acetal thing (I) under the catalysis of the copper salt with the peroxide tert-butyl acetate is generated by the reaction (II) shrinks the aldehydo-ester; 3, shrinks the aldehydo-ester (II) hydrolyzed under acidic conditions to obtain 4 - acetoxy - 2 - methyl - 2 - butenal. The method of starting material fed in cheap and easy to obtain, the process route is short, three wastes, synthetic route economic and effective.
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Paragraph 0074; 0077
(2019/01/08)
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- Preparation method of 4-acetoxy-2-methyl-2-crotonaldehyde
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The invention provides a preparation method of 4-acetoxy-2-methyl-2-crotonaldehyde. The preparation method comprises the following steps that (1) prenyl chloride is oxidized with oxygen under the effect of a catalyst into 4-chloro-2-methyl-2-crotonaldehyde; and 2) 4-chloro-2-methyl-2-crotonaldehyde and acetate are reacted to obtain 4-acetoxy-2-methyl-2-crotonaldehyde. The method is cheap and available in prenyl chloride as a starting material and short in process route as well as is economic and effective.
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Paragraph 0069; 0071; 0072
(2018/11/22)
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- Preparation method of 4-acetyloxy2-methyl-2-butenal
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The invention discloses a preparation method of 4-acetyloxy2-methyl-2-butenal. The method includes following steps: (1), feeding isoprene and Cl2 into an organic solvent containing a catalyst 1 and apolymerization inhibitor for addition reaction to obtain reaction liquid containing 1, 4-dichlorinated olefin; (2), enabling dichlorinated olefin obtained in the step (1) to react with an acetylationreagent under action of an acid binding agent, a cocatalyst and a catalyst 2 to obtain chlorinated olefin aldehyde alcohol ester; (3), allowing a product obtained in the step (2) to react with hexamethylenetetramine to generate 4-acetyloxy2-methyl-2-butenal. Isoprene and chlorine are used as starting raw materials, are common chemical raw materials and are low in cost and easy to obtain, and noblemetal catalysts are not needed, so that the preparation method is low in cost, simple to operate and little in environment pollution and is an effective synthetic route.
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Paragraph 0064; 0066; 0070; 0074; 0078; 0082; 0086; 0091
(2018/12/03)
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- METHOD OF MANUFACTURING 1-CHLORO-2-METHYL-4-ACYLOXY-2-BUTENE DERIVATIVES
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1-Chloro-2-methyl-4-acyloxy-2-butene derivatives can be synthesized in good yields and high purity starting from isoprene and employing a chlorohydrin formation reaction in a system made of N-chloroisocyanuric acid derivatives and water, followed by esterification and rearrangement of the crude product mixture.
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Page/Page column 4
(2008/06/13)
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- New retinoid analogs from δ-pyronene, a natural synthon
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δ-Pyronene (1), a readily available terpenic synthon, is an excellent raw material for the preparation of numerous terpenic intermediates. Original retinoid analogs such as 'iso'-retinyl acetate (5), 'iso'-retinal (6) and ethyl 'iso' retinoate (7), in which the cyclogeranyl moiety is functionalized in an unusual position, were prepared from δ-pyronene.
- Lambertin, Frederic,Wende, Martin,Quirin, Marie Jeanne,Taran, Martine,Delmond, Bernard
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p. 1489 - 1494
(2007/10/03)
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- REGIO-AND STEREOSELECTIVE PALLADIUM CATALYZED AMINATION OF ALLYLIC SUBSTRATES. SYNTHESIS OF E-4-AMINO-2-ALKEN-1-OL DERIVATIVES
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Under mild conditions 4, 5 and 6 react with primary and secondary amines in the presence of palladium phosphine complexes as catalysts to give 4-amino-2-alken-1-ols with (E) stereochemistry.
- Genet, J.P.,Balabane, M.,Baeckvall, J.E.,Nystoem, J.E.
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p. 2745 - 2748
(2007/10/02)
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