- Synthesis method of alpha-cyclocitral
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The invention discloses a synthesis method of alpha-cyclocitral. The method comprises the steps of (1) carrying out Diels-Alder reaction on 1,3-pentadiene and methylcrotonaldehyde under the catalysisof lewis acid to obtain a 2,6,6-trimethyl-3-cyclohexenyl formaldehyde crude product; (2) carrying out isomerization reaction on the 2,6,6-trimethyl-3-cyclohexenyl formaldehyde crude product obtained in step (1) under the catalysis of a catalyzer to generate an alpha-cyclocitral crude product. The method provided by the invention is easy to get reaction raw materials, mild in conditions, easy to control, free of generating byproducts, simple in process, favorable in industrial production, green and environmentally friendly.
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- Methylionone and preparation method of methylionone intermediate
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The invention discloses methylionone and a preparation method of a methylionone intermediate. According to an existing preparation method of methylionone, a lot of alkali usually needs to be wasted, and on the other hand, a lot of three wastes are caused. Under the conditions that citral and butanone serve as raw materials, PEG serves as a solvent and metal hydroxide serves as a condensation agent, an Aldol condensation reaction is conducted, and false methylionone is synthesized; the obtained false methylionone is subjected to a cyclization reaction catalyzed by acid, and methylionone is synthesized. According to methylionone and the preparation method of the methylionone intermediate, an adopted PEG-M(OH)x catalysis system improves the synthesis efficiency of the false methylionone, and the ratio of the false methylionone is kept at 68-79%; moreover, an adopted phosphoric acid-normal hexane catalytic cyclization system greatly improves the cyclization yield; an adopted catalytic condensation system can be used indiscriminately for several times, so that the cost is reduced, and environmental pollution is also reduced.
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Paragraph 0041; 0042
(2017/08/29)
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- CONTINUOUS PROCESS FOR PRODUCING PSEUDOIONONES AND IONONES
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The invention relates to a continuous process for producing pseudoionones of general formulas (I) and (I′) as well as isomers thereof, whereby: R1represents CH3 or (a); R2 and R3 represent hydrogen, CH3 or C2H5, and; R4 and R5represent hydrogen or CH3. These pseudoionones are produced by reacting an aldehyde of formula (II) with an excess of a ketone of general formula (III), whereby R1, R2 and R3 have the aforementioned meanings, in the presence of water and alkali hydroxide at an increased temperature and in a homogeneous solution. The inventive process is characterized in that: a) the intermixing of the homogeneous solution consisting of aldehyde, ketone and aqueous alkali lye occurs at a temperature ranging from 10 to 120 °C; b) the undissolved water and alkali hydroxide contained in the reaction mixture are subsequently separated out; c) while avoiding back mixing, the homogeneous reaction mixture is then guided through a reactor, which permits a residence time ranging from 2 to 300 minutes, at a temperature that is 10 to 120 °C higher than the boiling point of the lowest-boiling component and under a vapor pressure p ranging from 106 to 107 Pa; d) the reaction mixture is cooled by expansion; e) ketone is removed from the reaction mixture using vapor flowing in the opposite direction and; f) the raw product is dried and rid from excessive aldehyde and secondary components via a rectification column.
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Page/Page column 10
(2008/06/13)
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- Precursors for fragrant ketones and fragrant aldehydes
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The present invention refers to fragrance precursors of formula I for a fragrant ketone of formula II and one or more fragrant aldehydes or ketones of formula III and IV, These fragrance precursors are useful in perfumery, especially in the fine and functional perfumery.
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