547-64-8Relevant articles and documents
Two-Step Continuous-Flow Synthesis of Fungicide Metalaxyl through Catalytic C?N Bond-Formation Processes
Ishitani, Haruro,Yu, Zhibo,Ichitsuka, Tomohiro,Koumura, Nagatoshi,Onozawa, Shun-ya,Sato, Kazuhiko,Kobayashi, Shū
supporting information, p. 18 - 23 (2021/09/02)
Metalaxyl, an acylalanine fungicide, was synthesized through catalytic continuous sequential-flow reactions. Commonly used syntheses of this compound use batch systems and suffer from problems such as coproduction of halogen-containing by-products derived from acyl and alkyl halides in the substitution reactions of 2,6-dimethylaniline. To minimize waste and enhance efficiency, a halide-free approach including two continuous-flow catalytic processes, heterogeneous Pt-catalyzed reductive alkylation and homogeneous acid-catalyzed amidation with an acid anhydride, was developed. Systematic examination of the two reactions in flow mode enabled a high-yielding, two-step sequential continuous-flow process to be achieved. (Figure presented.).
Enhancing Effect of Residual Capping Agents in Heterogeneous Enantioselective Hydrogenation of α-keto Esters over Polymer-Capped Pt/Al2O3
Chung, Iljun,Song, Byeongju,Kim, Jeongmyeong,Yun, Yongju
, p. 31 - 42 (2021/01/11)
Heterogeneous enantioselective catalysis is considered a promising strategy for the large-scale production of enantiopure chemicals. In this work, polymer-capped Pt nanocatalysts having a uniform size were synthesized using poly(vinyl pyrrolidone) (PVP) and poly(vinyl alcohol) and supported on γ-Al2O3. After a facile heat treatment process, their catalytic performance for enantioselective hydrogenation of α-keto esters, a structure-sensitive reaction, was investigated. The presence of residual capping agents on the Pt surface often perturbs the adsorption of reacting species and reduces performance in structure-sensitive reactions. However, the 1 wt % PVP-Pt/Al2O3 catalyst exhibited an enhancement in both activity and enantioselectivity compared to a reference Pt/Al2O3 catalyst prepared by wet impregnation. Under optimized reaction conditions, the cinchonidine-modified PVP-Pt/Al2O3 gave an enantiomeric excess of 95% for the enantioselective hydrogenation of methyl pyruvate despite the low Pt loading. We demonstrate that depending on the type of polymers, the residual capping agents can lead to site-selective blockage of the Pt surface, that is, defects or terraces. Quantitative and qualitative analyses also show that the noticeable improvement in enantioselectivity is attributed to the stable adsorption of chiral modifiers on selectively exposed Pt terrace sites. The findings of this work provide a promising strategy to prepare metal nanoparticles having selectively exposed sites and offer insights into the enhancing effect of residual capping agents on the catalytic properties in structure-sensitive reactions.
Compound with litchi fragrance, preparation method of compound and daily essence
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Paragraph 0059-0064; 0080-0081; 0085-0086, (2021/05/12)
The invention relates to the field of spices, in particular to a compound with litchi fragrance, a preparation method of the compound and daily essence. The invention discloses a compound with litchi fragrance. The compound has a structure as shown in a formula (I). Research finds that the compound with litchi fragrance has obvious litchi fragrance, the fragrance intensity is high, and the fragrance is stable and lasting. The invention also provides a preparation method of the compound with litchi fragrance. The raw materials for preparing the compound with litchi fragrance are easy to obtain, the operation is simple, and the compound is suitable for wide popularization and application. The invention further provides a daily essence containing the compound with litchi fragrance.
Method for preparing methyl lactate through catalytic conversion of carbohydrate
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Paragraph 0078-0079; 0095-0096, (2022/01/04)
The invention discloses a method for preparing methyl lactate through catalytic conversion of carbohydrate. According to the method, an A-SCM-1 molecular sieve is used as a catalyst, a substrate carbohydrate is mixed with methanol, and methyl lactate is obtained through a one-step catalytic reaction. According to the method, efficient conversion of carbohydrate can be realized under mild reaction conditions, the selectivity of the product methyl lactate is high, and the catalyst has outstanding cycling stability and has a good industrial application prospect.
Conversion of sugars to methyl lactate with exfoliated layered stannosilicate UZAR-S4
Murillo, Beatriz,de la Iglesia, óscar,Rubio, César,Coronas, Joaquín,Téllez, Carlos
, p. 90 - 96 (2020/04/27)
Biomass has been shown as an alternative to fossil fuels for obtaining chemicals. In this work, the transformation of sugars into methyl lactate (ML) at 160 °C was carried out using the layered stannosilicate UZAR-S3 (University of Zaragoza-solid number 3) and the delaminated material UZAR-S4 (University of Zaragoza-solid number 4) obtained from its exfoliation. The exfoliation of UZAR-S3 to UZAR-S4 increased the accessibility of the compounds to the catalytic sites and the medium-strength acidity. Thus, the yield to ML for sucrose transformation increased from 8% for UZAR-S3 to 49.9 % for UZAR-S4. In the reusability tests, the UZAR-S4 catalyst was characterized before and after reaction by several techniques such as X-ray diffraction, thermogravimetry analysis, scanning electronic microscopy, energy dispersive X-ray spectroscopy and nitrogen adsorption. A deactivation of the catalyst was observed, which was related to carbonaceous deposits that decreased the specific surface area and the pore volume of the catalyst.
Bi-Functional Magnesium Silicate Catalyzed Glucose and Furfural Transformations to Renewable Chemicals
Kumar, Abhinav,Srivastava, Rajendra
, p. 4807 - 4816 (2020/08/24)
Bio-refinery is attracting significant interest to produce a wide range of renewable chemicals and fuels from biomass that are alternative to fossil fuel derived petrochemicals. Similar to petrochemical industries, bio-refinery also depends on solid zeolite catalysts. Acid-base catalysis plays pivotal role in producing a wide range of chemicals from biomass. Herein, the Mg framework substituted MTW zeolite is synthesized and explored in the valorisation of glucose and furfural. Bi-functional (acidic and basic) characteristics are confirmed using pyridine adsorbed FT?IR analysis and NH3 and CO2 temperature-programmed desorption techniques. Textural properties and morphological information are retrieved from N2-sorption, X-ray photoelectron spectroscopy, and electron microscopy. The activity of the catalyst is demonstrated in the selective isomerisation of glucose to fructose in ethanol. Glucose is converted to methyl lactate in high yield using the same catalyst. Further, the bi-functional activity of this catalyst is demonstrated in the production of fuel precursor by the reaction of furfural and isopropanol. Mg?MTW zeolite exhibits excellent activity in the production of all these chemicals and fuel derivative. The catalyst exhibits no significant loss in the activity even after five recycles. One simple catalyst affording three renewable synthetic intermediates from glucose and furfural will attract significant attention to catalysis researchers and industrialists.
Method for preparing lactate
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Paragraph 0070-0083; 0092-0101, (2020/06/30)
The invention relates to a method for preparing lactate. The method comprises the following steps of: contacting sugar and alcohol with a catalyst in a reactor, and reacting to obtain a lactate-containing product, wherein the molar ratio of the sugar to the alcohol is 1:(50-900), the reaction temperature is 150-250 DEG C, the reaction time is 10-50 hours, the catalyst contains a mixture of a titanium-silicon molecular sieve and a tin-silicon molecular sieve, and the weight ratio of the sugar to the mixture of the titanium-silicon molecular sieve and the tin-silicon molecular sieve based on drybasis weight is 1:(0.1-6). The method provided by the invention has high sugar conversion rate and high lactate yield.
Promotion effect of Mg on a post-synthesized Sn-Beta zeolite for the conversion of glucose to methyl lactate
Yang, Xiaomei,Lv, Bin,Lu, Tianliang,Su, Yunlai,Zhou, Lipeng
, p. 700 - 709 (2020/02/27)
Mg-Sn-Beta zeolites with different Mg/Sn molar ratios were prepared from the parent deAl-Beta by a coimpregnation method. The samples were characterized by powder X-ray diffraction (XRD), N2 physisorption, ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectroscopy of the -OH region and probe molecule (pyridine, CD3CN and CHCl3) adsorption. The results indicate that Mg2+ and Sn4+ can react with silanol nests and incorporate into the framework of Beta zeolite. Moreover, it is relatively facile to incorporate Sn4+ into the framework. The framework metal sites generate Lewis (L) acid sites; however, the L acid strength of the framework Mg2+ is weaker than that of framework Sn4+. A small amount of Mg2+ interacts with isolated silanols to form extraframework species. Therefore, the introduction of Mg2+ results in a significant reduction in silanol defects and an increase in L acidity/basicity of Mg-Sn-Beta. Mg-Sn-Beta with Mg/Sn molar ratio of 1 has the least silanol defects. In the conversion of glucose to methyl lactate (MLA), Mg-Beta is less active than Sn-Beta due to its weaker L acidity. The TOF value for MLA formation increased in the order of Sn-Beta 0.25Mg-Sn-Beta ≈ 4Mg-Sn-Beta 1Mg-Sn-Beta, which is closely related to the amount of silanol defects in the catalysts. A kinetic study indicates that the apparent activation energy of the retro-aldol of fructose to MLA, which is the rate-determining step of glucose conversion to MLA, decreases over Mg-Sn-Beta compared to that over Sn-Beta and thus, the formation of MLA was promoted.
Method for preparing lactate
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Paragraph 0070-0083; 0092-0101, (2020/06/30)
The invention relates to a method for preparing lactate. The method comprises the following steps: contacting pyruvic aldehyde and alcohol with a catalyst in a reactor, and reacting to obtain a lactate-containing product, wherein the molar ratio of the pyruvic aldehyde to the alcohol is 1:(20-225), the reaction temperature is 30-180 DEG C, the reaction time is 1-10 hours, the catalyst contains a mixture of a titanium-silicon molecular sieve and a tin-silicon molecular sieve, and the weight ratio of the pyruvic aldehyde to the mixture of the titanium-silicon molecular sieve and the tin-siliconmolecular sieve based on dry basis weight is 1:(0.1-6). The method provided by the invention has high pyruvic aldehyde conversion rate and high lactate yield.
Method for preparing lactate by catalyzing pyruvic aldehyde
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Paragraph 0163-0188; 0197-0204; 0210, (2020/07/02)
The invention relates to a method for preparing lactate by catalyzing pyruvic aldehyde. The method comprises the following steps: contacting pyruvic aldehyde and alcohol with a catalyst in a reactor,and reacting to obtain a lactate-containing product, wherein the molar ratio of pyruvic aldehyde to alcohol is 1:(50-225), the reaction temperature is 30-180 DEG C, the reaction time is 1-10 h, the reaction pressure is 0.1-3 MPa, the catalyst contains a tin-titanium-silicon molecular sieve, and the weight ratio of pyruvic aldehyde to the tin-titanium-silicon molecular sieve based on dry basis weight is 1:(1-6). According to the method, the catalyst containing the binary tin-titanium-silicon molecular sieve is adopted, framework tin atoms and framework titanium atoms of the molecular sieve synergistically catalyze pyruvic aldehyde and alcohol to generate lactate, and the reaction efficiency is improved.
