丁香酚催化氧化法合成香兰素

报道了一种由丁香酚催化合成香兰素的方法,即丁香酚在强碱性环境下转化为异丁香酚,然后以钴和镍盐为催化剂,氧气为氧化剂进行催化氧化获得香兰素。主要考察了反应温度、NaO H用量和氧气压力对异丁香酚氧化反应的影响。在最佳反应条件下,异丁香酚的转化率达到100%,香兰素的收率达到53%。该法绿色、环保、操作简单,具有一定的潜在工业实用价值。     

甲基三氧化铼催化过氧化氢氧化异丁香酚合成香兰素的研究

以异丁香酚为原料,叔丁醇为溶剂,CH_3ReO_3为催化剂,H_2O_2为氧化剂,进行氧化合成香兰素。采用单因素结合正交实验对异丁香酚氧化合成香兰素工艺进行优化。结果表明,最佳工艺条件为:反应温度70℃,反应时间4 h,催化剂用量0.9%(以异丁香酚的质量分数计)。在此条件下,反应稳定性较好,产物平均得率可达90.3%,产品香气较为纯正。采用IR、GC-MS、和~1H NMR等对产物进行了分析。     

甲基三氧化铼催化过氧化氢氧化异丁香酚合成香兰素的研究

以异丁香酚为原料,叔丁醇为溶剂,CH_3ReO_3为催化剂,H_2O_2为氧化剂,进行氧化合成香兰素。采用单因素结合正交实验对异丁香酚氧化合成香兰素工艺进行优化。结果表明,最佳工艺条件为:反应温度70℃,反应时间4 h,催化剂用量0.9%(以异丁香酚的质量分数计)。在此条件下,反应稳定性较好,产物平均得率可达90.3%,产品香气较为纯正。采用IR、GC-MS、和¹H NMR等对产物进行了分析。     

过氧磷钼钒酸盐催化合成乙酰基香兰素

以过氧磷钼钒酸十二烷基吡啶盐为催化剂、30%H2O2为氧化剂,催化氧化乙酰基异丁香酚合成了乙酰基香兰素。单因素实验结果表明,溶剂种类、反应温度、过氧化氢用量对反应有较大的影响;优化的工艺条件为:溶剂乙腈用量5mL、乙酰基异丁香酚用量1mmol、催化剂用量0.03g、过氧化氢用量6mmol、反应温度50℃、反应时间2h,在此条件下,乙酰基异丁香酚转化率和乙酰基香兰素选择性分别达到92.4%和64.2%。     

乙酸异丁香酚酯的合成研究

采用催化法合成乙酸异丁香酚酯。对影响酯化反应的主要因素,如催化剂的选择、催化剂用量、酯化温度和酯化时间等进行研究,得出了在无水碳酸钠催化下酯化反应的适宜条件为：酯化温度95℃~100℃,催化剂用量为异丁香酚的3%,异丁香酚和醋酐用量比为1：1.2（摩尔比）,酯化反应时间3h。     

非氧化还原金属离子加速Pd(Ⅱ)催化丁香酚双键异构化反应的研究

以Pd(OAc)_2和Al(OTf)_3为催化剂,研究非氧化还原金属离子加速Pd(Ⅱ)催化丁香酚双键异构化的反应。对不同的非氧化还原金属离子进行筛选,确定选用Al(OTf)_3为非氧化还原金属离子催化剂,采用单因素结合正交实验的方法对丁香酚的双键异构化工艺进行优化。结果表明,最佳工艺条件为:反应温度50℃,反应时间6 h,n[Al(OTf)_3]∶n[Pd(OAc)_2]=2∶1,Pd(OAc)_2和Al(OTf)_3的总用量为3.45%(以丁香酚的质量分数计)。在此条件下,反应稳定性较好,产物得率可达96.3%,其中反式异丁香酚的选择性为89.5%,产品香气较为纯正。采用IR、GC-MS、和¹H NMR等对产物进行了分析与表征。     

非氧化还原金属离子加速Pd(Ⅱ)催化丁香酚双键异构化反应的研究

以Pd(OAc)_2和Al(OTf)_3为催化剂,研究非氧化还原金属离子加速Pd(Ⅱ)催化丁香酚双键异构化的反应。对不同的非氧化还原金属离子进行筛选,确定选用Al(OTf)_3为非氧化还原金属离子催化剂,采用单因素结合正交实验的方法对丁香酚的双键异构化工艺进行优化。结果表明,最佳工艺条件为:反应温度50℃,反应时间6 h,n[Al(OTf)_3]∶n[Pd(OAc)_2]=2∶1,Pd(OAc)_2和Al(OTf)_3的总用量为3.45%(以丁香酚的质量分数计)。在此条件下,反应稳定性较好,产物得率可达96.3%,其中反式异丁香酚的选择性为89.5%,产品香气较为纯正。采用IR、GC-MS、和~1H NMR等对产物进行了分析与表征。     

钌金属配合物催化的丁香酚双键异构反应

以RuCl3·3H2O和三苯基膦制备钌金属配合物催化剂,研究钌金属配合物催化剂在不同溶剂中对丁香酚异构化反应的催化效果。研究结果表明,它在醇类等极性非质子溶剂中效果较好,其中以乙醇为溶剂时,转化率为98.3%,选择性为94.1%。在以乙醇为溶剂的条件下,考察了反应时间、催化剂用量、溶剂用量对丁香酚异构反应的影响,得出适宜的反应条件为:在乙醇回流温度下反应时间3 h,催化剂用量0.5%(按丁香酚质量比),溶剂用量300%(按丁香酚质量比)。在此条件下异丁香酚转化率为98.8%,其中反式异丁香酚选择性94.8%,得到的产品香气更为纯正。此外,还用红外、XRD和扫描电镜对RuCl2(PPh3)3催化剂进行了表征,研究了RuCl2(PPh3)3催化剂合成异丁香酚的反应机理。     

苄基异丁香酚制备工艺条件的改进

采用有机溶剂以取代水溶剂 ,并对影响反应收率及产品质量的主要工艺条件 :反应温度、物料配比、反应时间等进行了一系列试验 ,制备苄基异丁香酚最佳工艺条件为 :异丁香酚∶氯化苄∶氢氧化钾 =1∶1 0 4∶1 0 4(摩尔比 ) ,80℃反应 3 5h ,收率 90 % ,提高 6 %～ 8%。     

异丁香酚氧化制备香兰素工艺优化

采用正交试验法,对异丁香酚氧化制备香兰素的工艺进行了优化,在异丁香酚60 g,反应时间5 h,氧化剂108 g,碱液145 g的条件下,粗品得率大于55%,经乙醇重结晶精制后香兰素含量大于99%.该工艺比原工艺提高了产品的得率,纯化了产品香气.     

The influence of the tacticity on thermal degradation of PVC. III. Verification by ozonization of degraded samples

Two sets of ozonization reactions, for 1 h and 24 h respectively, have been carried out at ?20°C on degraded samples of PVC having different contents of tactic sequences. The evolution of the polyene sequences distribution with the ozonization was followed by UV-Visible spectroscopy. The number of chain scissions of ozonized samples was calculated from the number average molecular weight measurements before and after ozonization. The observed increase of short polyenes relative to the long polyenes with ozonization was found to depend markedly on the content of syndiotactic sequences. On the other hand, the number of chain scissions after total ozonization was found to be the higher the lower the content of tactic sequences in PVC samples is.     

Ozonization of humic acids in brown coal oxidized in situ

The effect of the ozonization of humic acids in chloroform and glacial acetic acid media on the yield and component composition of the resulting products was studied. The high efficiency of ozonization in acetic acid was found. Water-soluble low-molecular-weight substances were predominant among the ozonization products.     

Ozonolysis of the Semicoking Tar of Coal from the Shubarkol Deposit

The results of studies on the determination of the effect of ozonization on the hydrofining of coal tar from the coal of the Shubarkol deposit are reported. It was established that preliminary ozonization for 60 min makes it possible to increase the total yield of liquid products by 44.8% in the subsequent catalytic hydrogenation conversion of tar (5 MPa, 450°C, and a pseudo-homogeneous Mo-containing catalyst) and to increase the yield of a fraction with boiling points to 180°C by 17.7%, as compared with their concentrations in the parent tar.     

Investigation of the dimethyl acetal formation during the Ozonization of Alkenes in methanol

Dimethyl acetal formation during the ozonization of olefins in methanol followed by reduction with dimethyl sulfide has been occasionally reported in the literature. This acetalization can be completely suppressed, when the ozonization is carefully monitored by g.l.c. or t.l.c. analysis and stopped immediately after the consumption of the olefin. It was proved that the acetal formation observed earlier is the result of an acid catalysed reaction accelerated by dimethyl sulfide and dimethyl sulfoxide present in the reaction mixture. The acidic catalyst is formic acid formed from methanol by oxidation with excessive ozone.     

肉桂醛臭氧化反应过程的碘量法跟踪

在肉桂醛臭氧化反应过程中 ,分别用碘量滴定法和气相色谱法测定臭氧和肉桂醛的浓度变化 ,两者的结果有良好的线性关系 ,其线性方程为 :Y =1 2 0 73X + 0 0 0 0 2 ,相关系数为 0 995 ,并根据臭氧化反应机理对线性方程进行了讨论 ,结果表明可用简单的碘量滴定法监控复杂的臭氧化反应     

Cooling water treatment by ozonization

Ozonization of water in a cooling tower was investigated. A laboratory experimental set-up was employed to study changes in water quality during ozonization. Measured data were analyzed in the context of cooling water's resistance to corrosion, scaling and biofouling. A method is proposed for determining the suitable dosage of ozone for maintaining the necessary water quality. It has been found that ozonization is very effective in maintaining the correct water quality for the required purpose and provides an attractive alternative to the conventional multiple chemical method of cooling water treatment.     

Ozone treatment of water-soluble polymers. V. Ultraviolet irradiation effects on the ozonization of polyacrylamide

Polyacrylamide was ozonized in aqueous solution (at pH 2, 7, and 11) under UV irradiation with a low-pressure mercury lamp. The breakage of the polymer chains by ozone was strongly accelerated by UV irradiation under acidic and neutral conditions. Formaldehyde was produced characteristically in the UV ozonization. From the correlation between the amount of formaldehyde and the number of breaks of polymer chains, it was presumed that one molecule of formaldehyde resulted from the chain breakage, at least under acidic conditions. The intensity of the UV absorption peak at 266 nm (285 nm in the UV ozonization at pH 2), which was presumed to be due to the carbonyl groups, namely, ketone and terminal aldehyde produced by ozonization, was very much stronger than that in simple ozonization. Oxamic acid and oxamide as end products were observed in the solution which was ozonized exhaustively under UV irradiation.     

Reduction of nitrogen oxides by ozonization-catalysis hybrid process

Treatment of nitrogen oxides (NO_x) by using a hybrid process consisting of ozonization and catalysis was investigated. The ozonization method may be an alternative for the oxidation of NO to NO₂. It was found that nitric oxide (NO) was easily oxidized to nitrogen dioxide (NO₂) in the ozonization chamber without using any hydrocarbon additive. In a temperature range of 443 to 503 K, the decomposition of ozone into molecular oxygen was not significant, and one mole of ozone approximately reacted with one mole of NO. A kinetic study revealed that the oxidation of NO to NO₂ by ozone was very fast, almost completed in a few tens of milliseconds. When the amount of ozone added was less than stoichiometric ratio with respect to the initial concentration of NO, negligible NO₃ and N₂O₅ were formed. The oxidation of a part of NO to NO₂ in the ozonization chamber enhanced the selective reduction of NO_x to N₂ by a catalyst (V₂O₅/TiO₂), indicating that the mixture of NO and NO₂ reacts faster than NO.     

臭氧氧化处理法对聚丙烯表面涂装性的改良研究 Ⅰ.聚丙烯表面的臭氧氧化反应过程

讨论了用臭氧氧化法对聚丙烯表面进行涂装性改良时,聚丙烯均聚物、乙烯-丙烯嵌段共聚物及无规共聚物表面的臭氧氧化反应过程。ATR-IR、ESCA及SEM的结果表明,3种聚丙烯有相同的反应过程,即臭氧氧化反应首先使材料表面的聚丙烯部分生成PP-OH和PP-C=CH,然后-C=C-被臭氧氧化分解生成酮、醛或羧基等,最终氧化产物以羧基为主。臭氧氧化主要发生在处于材料表面非晶态中的丙烯叔H部分上。但由于臭氧对聚丙烯及其共聚物表面的攻击方式不同,溶剂洗净后3种聚丙烯状态将有很大的差异。     

Pilot run,plant design and cost analysis for reductive ozonolysis of methyl soyate

Preparation of methyl azelaaldehydate dimethyl acetal (MAzDA) from methyl soyate was investigated on a pilot scale via the sequence ozonization, hydrogenation, acetalization and fractional distillation. A water-methyl soyate emulsion for the ozonization step was preferred to methanolic solution or neat methyl soyate for reasons of cost and safety. Ozonization of the water-methyl soyate emulsion (1.63:1 ratio) in a six-plate sieve tower produced 1271 lb aqueous peroxidic emulsion during 12 days of continuous operation. Because a continuous hydrogenation facility was not available, reduction was done in 200 lb batches. Since batch hydrogenation of the peroxidic emulsion in this quantity was difficult to control and optimum conditions were difficult to maintain, maximum yield of the product was only 56%. The average yield for seven batches was 48.3%. However laboratory hydrogenation under optimum conditions of periodic samples taken from the sieve tower discharge indicated an overall yield of 74.5% (average of eight monitor samples). A plant designed to produce 10 million lb annually should be capable of producing MAzDA at a total manufacturing cost of 39 cents/lb or a net manufacturing cost of 27 cents/lb with byproduct credit conservatively estimated. Methyl soyate ozonolysis products are not sensitive to detonation, and their exothermic decomposition is greatly moderated by the presence of water. Presented in part at the AOCS Meeting, New Orleans, May 1967; see Abstr. 117, JAOCS 44:139A (1967). ARS, USDA.