504-02-9Relevant articles and documents
Method for preparing 1, 3-cyclohexanedione
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Paragraph 0026-0032, (2021/09/04)
The invention discloses a method for preparing 1, 3-cyclohexanedione. The method comprises the following steps: 1) dissolving acetylacetone and a catalyst in a solvent, adding acrylate into a constant-pressure dropping funnel, and dropwise adding acrylate into a reaction system, after drop-by-drop adding, heating to 60-80 DEG C, and continuously reacting for 0.5-1 hour; and 2) after the reaction is finished, cooling to 40 DEG C, adding a solid condensing agent, heating the reaction liquid to 40-50 DEG C, continuously reacting for 1-1.5 hours, concentrating under reduced pressure to remove the solvent and methyl acetate and other low-boiling-point byproducts generated by the reaction, then adding a small amount of water, adjusting the pH value to 1-2 by using hydrochloric acid (1.1-1.2 equivalent), cooling to separate out a product, centrifuging, leaching by using a small amount of ice water, carrying out pulping treatment by using ethyl acetate, filtering and drying to obtain the 1, 3-cyclohexanedione product.
Preparation method of 1,3-cyclohexanedione
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Paragraph 0013; 0026-0030; 0036-0045; 0061, (2020/06/09)
The invention relates to the technical field of chemical synthesis, in particular to a preparation method of 1,3-cyclohexanedione. The preparation method of the 1,3-cyclohexanedione comprises the following steps: with 1,3-acetonedicarboxylic ester and acrylate as raw materials, carrying out condensation and cyclization under the action of a base catalyst to prepare an intermediate; carrying out hydrolysis decarboxylation on the intermediate to obtain a crude product; and recrystallizing the crude product to obtain the 1,3-cyclohexanedione. The preparation method of the 1,3-cyclohexanedione hasthe advantages that process conditions are convenient to realize, post-treatment operation process is simple, yield is as high as 90.9%, reaction selectivity is high, production efficiency is high, operation safety is high, pollution is small, and the preparation method is suitable for industrial scale production.
Rapid and Multigram Synthesis of Vinylogous Esters under Continuous Flow: An Access to Transetherification and Reverse Reaction of Vinylogous Esters
Mohanta, Nirmala,Chaudhari, Moreshwar B.,Digrawal, Naveen Kumar,Gnanaprakasam, Boopathy
, p. 1034 - 1045 (2019/05/24)
An environmentally benign approach for the synthesis of vinylogous esters from 1,3-diketone and its reverse reaction under continuous-flow has been developed with alcohols in the presence of inexpensive Amberlyst-15 as a catalyst. This methodology is highly selective and general for a range of cyclic 1,3-dicarbonyl compounds which gives a library of linear alkylated and arylated vinylogous esters in good to excellent yield under solvent and metal free condition. Furthermore, the long-time experiment in a continuous-flow up to 40 h afforded 8.0 g of the vinylogous ester with turnover number (TON) = 28.6 and turnover frequency (TOF) = 0.715 h-1 using Amberlyst-15 as a catalyst. Furthermore, a continuous-flow sequential transetherification of vinylogous esters with various alcohols has been achieved in high yield. Reversibly, this vinylogous ester was deprotected or hydrolyzed into ketone using environmentally benign water as a solvent and Amberlyst-15 as a catalyst under continuous-flow process.