溴酸钠氧化制乙偶姻

乙偶姻作为香料产品,广泛用于食品、饮料、烟酒中。开发了一种以丁酮为原料,经溴酸钠氧化,然后在碱性条件下水解二步合成3-羟基-2-丁酮的方法。探讨了物料比、酸度、温度、时间对反应的影响,得出最佳反应条件为物料摩尔比（丁酮：溴酸钠：氢氧化钠=1：1.2：1）,酸浓度10%,反应温度45℃,总反应时间9h。该反应条件温和,操作简便,纯化容易,总收率为62%左右,产物纯度达99%以上。     

乙偶姻合成研究现状及展望

综述了由丁二酮和丁二醇两种原料合成乙偶姻的研究现状,分析了乙偶姻合成研究的发展趋势。     

食用香料乙偶姻

乙偶姻是国际上常用的香料品种,主要用作配置奶油、乳品、酸奶和草莓等型的香料。其合成方法很多,国内外主要的工业化方法是以2,3-丁二酮为原料的合成方法。安徽省化工研究院开发了丁酮氯化法新工艺,该方法具有原料成本低、产品质量高、产率较高、工艺操作简单、三废少且易于处理等优点。目前已建成年产10t的生产装置,并计划在2002年扩大到50t/a。     

合成溴代丁酮的新工艺研究

采用溴化钠饱和溶液-浓硫酸-双氧水溴化丁酮原位合成溴代丁酮,考察了反应温度、双氧水浓度、双氧水滴加时间、双氧水用量和溴化钠用量等因素对反应的影响。结果表明,在50℃时,往含有0.2mol溴化钠、0.1mol浓硫酸和0.16mol丁酮混和物中,60min内滴入50%浓度的双氧水0.2mol,搅拌2h,丁酮转化率达到81.2%,3-溴-2-丁酮的产率达到60.5%。     

一种2,3,5,6-四甲基吡嗪的简便合成方法研究

利用磷酸氢二铵促进梅拉德反应的性质,通过其与3-羟基-2-丁酮反应合成2,3,5,6-四甲基吡嗪,同时比较考察了3-羟基-2-丁酮与不同铵盐的反应。结果表明,3-羟基-2-丁酮与磷酸氢二铵在室温条件下静置24 h,过滤洗涤即得到2,3,5,6-四甲基吡嗪,产率可达到50%以上,且操作简便,适于工业开发。     

邻碘酰苯甲酸氧化乙偶姻合成丁二酮

以邻碘酰苯甲酸(IBX)为氧化剂,对乙偶姻氧化合成丁二酮的反应进行研究。考察了影响反应的因素,得出了其优化反应条件为:邻碘酰苯甲酸与乙偶姻的物质的量比为1.2∶1,用叔丁醇作溶剂,反应温度为70℃,反应时间40 min,产率达95%。氧化剂和溶剂均可以回收利用。     

3-羟基-2-丁酮合成2,3,5,6-四甲基吡嗪的研究

对利用3-羟基-2-丁酮合成2,3,5,6-四甲基吡嗪的过程进行了研究,考察了不同反应温度、时间、真空度、3-羟基-2-丁酮与铵盐物质的量比和pH值的影响规律。结果表明：3-羟基-2-丁酮、乙酸铵物质的量比在1∶1.4,pH值为6,反应初期温度40℃,反应时间1h,后期温度90℃,真空度（绝对压力）3000Pa,反应时间控制在2h时,2,3,5,6-四甲基吡嗪总收率可达到87.5%以上。     

2-溴甲基-3-羟基吡啶合成工艺的改进

2-溴甲基-3-羟基吡啶是合成常山酮的中间体,以3-羟基吡啶为起始原料,经胺甲基化、醋酐乙酰化、浓氢溴酸水解3步反应,合成2-溴甲基-3-羟基吡啶,总收率达56.79%。通过MS和1 H NMR对化合物结构进行表征。该方法原料是工业级,反应条件平和,对设备的要求不高,可以满足工业化路线的要求。     

微波辐射三氯化铁氧化乙偶姻合成丁二酮

微波辐射下以三氯化铁为氧化剂,对乙偶姻氧化合成丁二酮的反应进行研究。考察了影响反应的因素,得出了其最佳的反应条件为:乙偶姻与三氯化铁的物质的量比为1∶1.3,用水作溶剂,400 W微波辐射10min,产率达81.41%。     

3-羟基-2-丁酮气相催化脱水制4-己烯-3-酮的研究

叙述了以3-羟基-2-丁酮(丙偶姻)为原料,在HZSM-5催化剂作用下脱水生成相应的4-己烯-3-酮。反应在常压下进行,反应温度380~430℃,液体体积空速1.5~2.5 h-1,转化率高达99%,4-己烯-3-酮总收率为82%。反应过程中仅有少量废水排放,具有绿色环保、节能、高效的优点。     

Efficient acetoin production from pyruvate by engineered Halomonas bluephagenesis whole-cell biocatalysis

Acetoin is an important platform chemical, which has a wide range of applications in many industries. Halomonas bluephagenesis, a chassis for next generation of industrial biotechnology, has advantages of fast growth and high tolerance to organic acid salts and alkaline environment. Here, α-acetolactate synthase and α-acetolactate decarboxylase from Bacillus subtilis 168 were co-expressed in H. bluephagenesis to produce acetoin from pyruvate. After reaction condition optimization and further increase of α-acetolactate decarboxylase expression, acetoin production and yield were significantly enhanced to 223.4 mmol·L^–1 and 0.491 mol·mol^–1 from 125.4 mmol·L^–1 and 0.333 mol·mol^–1, respectively. Finally, the highest titer of 974.3 mmol·L^–1 (85.84 g·L^–1) of acetoin was accumulated from 2143.4 mmol·L^–1 (188.6 g·L^–1) of pyruvic acid within 8 h in fed-batch bioconversion under optimal reaction conditions. Moreover, the reusability of the cell catalysis was also tested, and the result illustrated that the whole-cell catalysis obtained 433.3, 440.2, 379.0, 442.8 and 339.4 mmol·L^–1 (38.2, 38.8, 33.4, 39.0 and 29.9 g·L^–1) acetoin in five repeated cycles under the same conditions. This work therefore provided an efficient H. bluephagenesis whole-cell catalysis with a broad development prospect in biosynthesis of acetoin.     

气相色谱法分析2,3-丁二酮

建立了一种利用气相色谱测定丁二酮的定量分析方法。采用FID检测器和HP-5毛细管色谱柱,对2,3-丁二酮进行定量分析。以该方法测定2,3-丁二酮的平均回收率为101.5%,标准偏差（峰面积响应值）为18.5818,变异系数为0.59%,线性决定系数（r2）为0.9999。结果表明该方法适用于2,3-丁二酮的定量分析。     

在线红外光谱对2,3-丁二酮单肟钠盐的合成反应过程研究

利用在线红外光谱对2,3-丁二酮单肟钠盐的合成反应进行了在线监测,通过监测反应物2-丁酮（1719cm?1）、中间体2,3-丁二酮单肟（1693cm?1和3249cm?1）和乙醇（1026cm?1）以及最终产物2,3-丁二酮单肟钠盐（1643cm?1）特征峰的变化,推断了反应体系中各组分浓度的变化规律,从而比较清楚地了解了该反应的进程。结果表明,在线红外光谱能够快速、简便、准确地确定出反应结束时间,从而达到对合成反应过程进行控制的目的。     

异丁醇催化胺化制备异丁胺

采用沉淀-沉积法研制Co-Ni-Zn-Fe/HZSM-5催化剂,用于异丁醇胺化反应合成异丁胺。通过对该反应过程不同载体、活性组分不同配比的研究,确立了该催化体系中最适宜的活性金属组成为22.5%Co、12.8%Ni、3.0%Zn、1.5%Fe。并在压力1.2Mpa、氨醇摩尔比8∶1、温度185℃、醇液体空速0.6～0.8h?1最佳反应条件下,异丁醇的单程转化率达到98.5%,在有效抑制三异丁胺等副产物合成的同时,使一异丁胺和二异丁胺的总选择性达到99.8%,大大提高了合成反应的效能,为异丁胺的高效生产提供了新的方法,具有较好的工业应用价值。     

介孔氧化铝的制备研究及催化应用

介孔氧化铝作为一种新型多功能介孔材料被应用于催化、吸附分离、医药等领域。本文简要介绍了介孔氧化铝及负载型介孔氧化铝的制备以及重点介绍其在催化反应中的应用。介孔氧化铝早日成为工业化产品是我们共同的目标。     

Preparation of Mg‐Al hydrotalcite by urea method and its catalytic activity for transesterification

Layered double hydroxides based on the structure (Mg₆Al₂(OH)₁₆CO₃·4H₂O) were synthesized by urea hydrolysis method and characterized by XRD, FTIR, SEM, and EDS. The results revealed that pH played a crucial role in the Mg‐Al hydrotalcite precipitation by controlling [urea]/[NO] molar ratio in reaction solution at 378 K and the optimized [urea]/[NO] molar ratio was 4.0. The sample calcined at 773 K was used as a solid catalyst for biodiesel synthesis. The catalyst was found to have a high catalytic activity in transesterification of rape oil to methanol with about 94% oil conversion at 338 K for 3 h. The water content of the oil could be kept below 2.0 wt % and free fatty acid content of the oil could be kept below 3.0 mg KOH·g[oil]^?1 in order to get the best conversion. So, the solid catalyst was more tolerant to free fatty acid and water in rape oil than homogeneous basic‐catalysts. Moreover, the catalyst could be reused, but catalytic activity decreased on reuse of the catalyst although it remained highly active for the five uses. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

枯草芽孢杆菌发酵甘草渣产2,3-丁二醇和乙偶姻的初步研究

甘草渣是甘草提取完活性成分后的剩余物，富含木质纤维素。以甘草渣为研究对象，以2种稀碱（Na2CO3水溶液和NaOH水溶液）以及稀碱（Na2CO3水溶液或NaOH水溶液）和醋酸乙醇胺离子液体混合液为溶剂对甘草渣进行预处理，研究不同碱浓度和预处理温度对甘草渣组成及酶解效果的影响。结果表明，质量分数2%的NaOH水溶液在固液比（w/v）1:10（即每克甘草渣加入10毫升溶剂）、100 ℃条件下预处理甘草渣1.5 h，木质素去除率达54.1%、纤维素回收率为77.2%；样品酶解24 h，葡萄糖得率可达53.5%，较预处理前甘草渣（10.6%）提高了4.0倍。最后，对预处理后的甘草渣进行高固酶解，在固液比3:10、酶用量45 FPU/g生物质条件下酶解72 h，葡萄糖产量达到86.2 g/L、木糖18.9 g/L。以此酶解液为碳源进行发酵，96 h后发酵液中2,3-丁二醇和乙偶姻总产量为43.9 g/L，还原糖转化率为0.42 g/g；与对照组相比，酶解液更有利于菌体生长，生产强度提高，但转化率略低。     

Efficient acetoin production by optimization of medium components and oxygen supply control using a newly isolated Paenibacillus polymyxa CS107

BACKGROUND: Acetoin is a natural flavor commonly used in wine, buffer, honey, garnet berry and strawberry as a food additive. It also has been widely applied in cosmetics, pharmacy and chemical synthesis. Culture medium optimization and process control were carried out for efficient production of acetoin by a newly isoliated P. polymyxa CS107. RESULTS: An acetoin high producing strain, designated as CS107, was newly isolated and identified as P. polymyxa based on its physiological and biochemical characteristics as well as the 16S rDNA sequence. The medium composition was optimized in shake flask fermentations by a sequential statistical experimental design. Under the optimized conditions, acetoin concentration of 30.98 g L^?1 was achieved with 71.83% of theoretical glucose conversion efficiency. Fed‐batch fermentation based on a suitable agitation speed was carried out in a 5 L jar, the maximum acetoin concentration of 55.3 g L^?1 was obtained with the productivity of 1.32 g L^?1 h^?1 and the yield of 75.62%. CONCLUSION: A new strain for efficient production of acetoin, designated as P. polymyxa CS107, was obtained. The optimization of fermentation variables and fed‐batch culture resulted in a maximum acetoin concentration of 55.3 g L^?1 in 5 L jar. Copyright © 2012 Society of Chemical Industry