二氢茉莉酮酸甲酯生产工艺的研究

二氢茉莉酮酸甲酯是一种深受人们喜爱的茉莉香型的重要香原料。本文以环戊酮和戊醛为原料在碱催化下 ,以缩合和异构化反应合成了 2 -戊基环戊烯酮。 2 -戊基环戊烯酮再与丙二酸二甲酯缩合 ,脱羧得二氢茉莉酮酸甲酯 ,并且进行了中试放大 ,确定了最佳工艺条件     

Baeyer–Villiger-oxidation of cyclopentanone with aqueous hydrogen peroxide by acid heterogeneous catalysis

Using aqueous hydrogen peroxide containing 30% H₂O₂, solid acid catalysts were compared in their performance as catalysts for the transformation of cyclopentanone to δ-valerolactone. It could be shown that organic ion exchange resins with sulphonic acid groups providing acid functionality are promising catalysts for this reaction. The variation of several reaction parameters was studied in more detail. The obtained results were compared to investigations of zeolites and Nafion^® composite materials.     

Thioreduction of cyclopentanone and hydrodesulfurization of dibenzothiophene over sulfided nickel or cobalt-promoted molybdenum on alumina catalysts

Two series of sulfided Ni or Co promoted Mo/alumina catalysts, having different Ni or Co loadings, were characterized by their activities for the transformation of cyclopentanone into cyclopentanethiol (flow reactor, 220°C, atmospheric pressure) and for the hydrodesulfurization of dibenzothiophene (flow reactor, 340°C, 3 MPa hydrogen pressure). The addition of the promoter increased significantly the activity of the Mo/alumina catalyst for both reactions, up to a maximum obtained with the catalysts having a (promoter)/(promoter+Mo) molar ratio equal to 0.3–0.4. This increase in activity was due in part to an increase in the hydrogenating properties of the Mo/alumina catalyst. However, an additional modification of the catalyst (basic and nucleophilic properties) must be considered to account for the spectacular effect of the promoter on the rate of the dibenzothiophene direct desulfurization reaction.     

三甲基戊基环戊酮的合成

利用环戊酮与正戊醛缩合，再经催化氢化制得了２－正戊基环戊酮。研究了环戊酮与正戊醛羟醛缩合反应生成２－亚正戊基环戊酮的各种影响因素，２－正戊基环戌酮与碘甲烷反应合成了三甲基戊基环戊酮香料单体。     

商品十八烷基聚氧乙烯醚用于气相色谱固定液

用商品十八烷基聚氧乙烯醚经电渗析制备了气相色谱固定液，用该固定液对环戊酮及环戊醇混合物进行了定性、定量分析，该固定液使用寿命可达１２个月以上。     

磷化镍的制备及其催化糠醛加氢制备环戊酮

以NiCl_2·6H_2O为镍源、NaH_2PO_2·H_2O为磷源、乙二醇为溶剂、n(P)∶n(Ni)=3∶1,采用溶剂热法制备得到磷化镍(Ni-P)催化剂,并采用XRD、SEM、TEM、H_2-TPR、H_2-TPD、N_2吸附-脱附、XPS对其进行了表征。催化剂应用于糠醛加氢制备环戊酮的反应中效果良好,并考察了催化剂用量、氢气压力、反应温度、反应时间对反应的影响。结果表明,较优的工艺条件为:以水作为溶剂,原料与催化剂质量比为12,在反应温度150℃、氢气压力2.0 MPa、反应时间4 h时,糠醛转化率达到98.87%,环戊酮收率为68.65%。对催化剂进行稳定性测试,4次重复使用后环戊酮收率仅下降3.25%。     

Preparation of Ni(Co)–W–B amorphous catalysts for cyclopentanone hydrodeoxygenation

Ni–Co–W–B, Ni–W–B and Co–W–B catalysts were prepared by chemical reduction method and showed high activity in the HDO of cyclopentanone. Co–W–B had higher thermal stability than Ni–Co–W–B and Ni–W–B catalyst. The conversion of cyclopentanone could be high to 96.6% with a cyclopentanol selectivity of 0.4% and a deoxygenation rate of 95.4%. The HDO activity of the catalyst was related to its thermal stability, surface area, hydrogen supplying ability and Brönsted acid sites.     

二氢茉莉酮酸甲酯的合成

利用尼龙酸副产物中含有的环戊酮 ,合成了二氢茉莉酮酸甲酯 .对正戊醛的加入方式、滴加时间、催化剂浓度、反应温度、原料配比等对转化率和选择性的影响进行了研究 .利用元素分析、GCMS、IR、1HNMR等手段对产物进行了定性测试 ,结果表明 ,所合成产物是二氢茉莉酮酸甲酯 .本方法能有效地控制副反应 ,使中间产物 2 -亚正戊基环戊酮产率达到 89% .可以用于尼龙酸副产物的综合利用     

Cyclopentanone: A raw material for production of C15 and C17 fuel precursors

The synthesis of diesel or jet fuels intermediates from furfural or 5-hydroxymethylfurfural (HMF) via aqueous aldol-condensation with cyclopentanone was studied. Cyclopentanone is the product of furfural rearrangement in an aqueous system. Since the aldol-condensation reaction is conducted in an aqueous solution all these biomass-derived reactants can be applied as water solutions formed in the processes of their preparation. The aldol condensation of furfural with cyclopentanone is at low concentration of base and molar ratio of reactants 2:1 highly selective and after 40–80 min of reaction at a temperature of 40–100 °C more than 95 mol% yield of 2,5-bis (2-furylmethylidene) cyclopentan-1-one (F₂C) was obtained. When instead of furfural as a reactant HMF was used higher than 98 mol% yield of 2,5-bis (5-hydroxymethyl-2-furylmethylidene) cyclopentan-1-one was achieved. The final products of aldol condensation of furfural and HMF are exclusively corresponding dimers, what enables to obtain after subsequent hydrogenation/hydrodeoxygenation step dialkylcyclopentane type of diesel or jet fuels having C₁₅ or C₁₇ molecules.     

Synergy between Ni3Sn2 alloy and Lewis acidic ReOx enables selectivity control of furfural hydrogenation to cyclopentanone

Selectivity controlling is a crucial and challenging issue for the hydrogenation of furfural (FAL) to cyclopentanone (CPO). Herein, Ni₃Sn₂-ReO_x/TiO₂ is synthesized via successive impregnation and exhibits full conversion and 92.5 % CPO selectivity under 3.0 MPa H₂ at 140 °C, which are much higher than those of Ni/TiO₂ and Ni₃Sn₂/TiO₂. Characterizations show that Ni₃Sn₂ is the main active phase that remarkably restrains the over-hydrogenation of the furan ring, while ReO_x plays an electrophile or Lewis acid site to activate C-OH of furfuryl alcohol and induces its rearrangement. DFT calculations verify that Sn doping weakens the furan ring adsorption on Ni₃Sn₂ and shifts its adsorption configuration, which consequently inhibits side reactions and favors the metal-acid (Ni₃Sn₂-ReO_x) synergy. The catalyst is stable, recyclable and also active at even 0.5 MPa H₂ and 80 °C. This study provides an advanced strategy for the rational design of superior catalysts for tuning product selectivity, with practical potential for upgrading biomass-derived platform molecules.