28940-11-6Relevant articles and documents
KI-catalysed synthesis of 4-methylcatechol dimethylacetate and fragrant compound Calone 1951
Zhang, Ya-Zheng,Yang, Qian,Huang, Shao-Jian,Luo, Zi-Ping,Li, Wen-Ping,Dong, Li-Chun
, p. 586 - 593 (2013)
Synthesis of the fragrant compound Calone 1951 from 4-methyl catechol and methyl bromoacetate entails three successive reactions: the Williamson reaction, Dieckmann condensation, and hydrolysis-decarboxylation reaction. In this paper, the synthesis of 4-methylcatechol dimethylacetate (MCDA) via the Williamson reaction by adding KI as catalyst was investigated. It was found that the addition of an appropriate amount of KI can significantly increase the product yield due to generation of methyl iodoacetate via the reaction between KI and methyl bromoacetate. The synthesised MCDA as well as Calone 1951 were first characterised by melting points, HPLC, IR, and NMR analyses. Next, the effect of the key operating factors on MCDA synthesis by the Williamson reaction was investigated and the optimum operating conditions were obtained via a group of orthogonal experiments. The verification experiments demonstrated that, under the optimum operating conditions, the MCDA yield could be increased from 78.5 % to 95.4 % by the addition of an appropriate amount of KI; the corresponding yield of Calone 1951 increased to 68 %.
Preparation method of watermelon ketone
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Paragraph 0059-0143, (2021/08/14)
The invention relates to a preparation method of watermelon ketone, which comprises the following steps: by taking 4-methylcatechol and 1,3-dichloroacetone as raw materials and carbonate as a base catalyst, adding a drying agent into a Soxhlet extractor for dehydration, and under the protection of inert gas, assembling a reduced pressure reflux water removal device to prepare a watermelon ketone crude product; carrying out rotary evaporation to recover a solvent, carrying out post-treatment steps of decoloration, concentration and the like, and transferring an obtained solution into a rectification device provided with a glass vacuum rectification column to carry out segmented rectification: in first-stage rectification, evaporating off reaction solvent light components, in second-stage rectification, collecting fractions to obtain a residual raw material 4-methylcatechol and a part of crude product watermelon ketone, and in third-stage rectification, collecting a main fraction watermelon ketone crude product; and recrystallizing the watermelon ketone crude product. According to the preparation method of the watermelon ketone, the yield of the watermelon ketone is improved through the reduced pressure reflux water removal device, the watermelon ketone is purified step by step by combining segmented rectification and recrystallization, the purity of the product reaches 98% or above, the technological process is simplified, and the problem that industrial large-scale production is difficult to achieve through an existing watermelon ketone synthesis technology is solved.
A Deoximation Method for Deprotection of Ketones and Aldhydes Using a Graphene-Oxide-Based Co-catalysts System
Tong, Qiaolin,Liu, Yang,Gao, Xuezhi,Fan, Zhanfang,Liu, Tianfu,Li, Bo,Su, Dangsheng,Wang, Qinghe,Cheng, Maosheng
supporting information, p. 3137 - 3145 (2019/05/01)
The deoximation of a wide range of ketoximes and aldoximes to their corresponding carbonyl compounds with high yields has been achieved using graphene oxide (GO) and sodium nitrite (NaNO2) as highly efficient catalysts and air as the green oxidant under mild conditions. The mechanism of deprotection and recycling use of catalyst were revealed in deep experiment. The carboxylic acid groups on the GO were essential for high catalytic activity. (Figure presented.).