3，3-二乙氧基丙腈

3,3-二乙氧基丙腈是合成维生素B1、胞嘧啶及其衍生物等重要化合物的前体。综述了3,3-二乙氧基丙腈的合成方法,包括酰胺脱水、金属氰化物取代、醚化和异噁唑法,用于工业化生产较为满意的合成路线是以1,1,3,3-四乙氧基丙烷为原料的异噁唑法。     

维生素B6合成中的Diels-Alder反应及重排机理研究

4-甲基-5-乙氧基噁唑与2-正丙基-4,7-二氢-1,3-二氧七环之间的Diels-Alder反应是合成维生素B6传统工艺的关键反应,加成物经过重排即生成维生素B6的前体,经水解脱保护后再成盐即制得维生素B6相关酸加成盐。文章通过分离纯化并鉴定加成反应产物及后续重排反应的中间体,对加成反应的exo/endo选择性及重排反应的机理过程进行了讨论,这些结果将被用于对exo/endo选择性和反应体系收率影响进行研究。     

PVF热稳定剂

用N-苯并噁唑啉酮衍生物可减少PVF加工过程中的氧化热降解。用N-苯并噁唑啉酮钾盐、N-苯并恶唑啉酮-β-丙腈和双苯并噁唑啉酮稳定的PVF在513°K6小时的重量损失比未稳定的PVF,分别从13%的降到     

2-对甲苯基苯并??唑合成方法综述

在深入研究报道的苯并噁唑类化合物合成方法及分析2-对甲苯基苯并噁唑化合物结构特点的基础上,以2-对甲苯基苯并噁唑为代表,以合成苯并唑环为主线,归纳出拉登堡(Ladenburg)苯并噁唑合成法、类-拉登堡苯并噁唑合成法及非-拉登堡苯并噁唑合成法三大合成途径。按合成原料类别分类,系统概述了2-对甲苯基苯并噁唑合成路线和合成方法。列出了各反应的主要条件和收率,讨论了部分路线的反应机理,给出了一些研究建议。     

2,6-二氯苯并噁唑生产废水中氨氮的检测研究

以2-巯基-6-氯苯并噁唑和固体光气为起始原料,DMF为催化剂,在甲苯溶液中合成2,6-二氯苯并噁唑,反应尾气用10%液碱吸收。分别用稀释法、絮凝沉淀法、蒸馏法对尾气吸收废水进行预处理,然后再用纳氏分光光度法检测水样的氨氮浓度。结果表明,絮凝沉淀法能有效屏蔽2,6-二氯苯并噁唑尾气吸收废水中硫化物对氨氮检测的干扰,氨氮检测快捷准确。     

恶唑禾草灵防除麦田看麦娘等禾本科杂草

噁唑禾草灵(Puma Super)系西德Hoechst化学公司研制产品,用于防除麦田禾本科杂草的茎叶处理剂,试验代号Hoe 046360,化学名称为(R)-2-〔4-(6-氯-2-苯并噁唑氧基)苯     

精噁唑禾草灵中间体2，6-二氯苯并噁唑合成工艺改进

介绍了以2-巯基-6-氯苯并(噁)唑、氯化亚砜、甲苯、DMF为起始原料制备2,6 -二氯苯并(噁)唑的改进工艺,得到产物的纯度为96%、收率 81.8%以上,具有收率高、反应过程稳定、操作简单、生产成本低等优点.     

新环3-氧代-5H-5-取代芳基异嗯唑[3，4-e]并-1，2，3，4．四嗪衍生物的合成

合成了6种3-氨基-5-氧代-4-芳基偶氮异噁唑衍生物和3-氧代-5-取代芳基异噁唑[3，4-e]并-1，2，3，4-四嗪衍生物，经元素分析、IR和质谱分析确定了其结构。     

具有农药活性物1,3,4-噁二唑硫醚类化合物研究进展

1,3,4-噁二唑硫醚衍生物具有广谱生物活性,从抑菌、杀虫、除草及抗病毒等农药活性方面综述了1,3,4-噁二唑硫醚类化合物研究进展,期望为1,3,4-噁二唑硫醚衍生物在农业方面的应用提供依据。     

2,2-(2,2'-4(S)-苯基-4,5-二氢(噁)唑啉基)丙烷金属络合物对硝酮环加成反应的催化作用

研究了手性双噁唑啉配体2,2-（2,2’-4（S）-苯基-4,5-二氢噁唑啉基）丙烷（5）与铜或锌的配合物对二苯基硝酮（8）与3-（（E）-2-丁烯酰基）-1,3-噁唑烷-2-酮（6）和2,3-二氢呋喃（7）两种烯烃的环加成反应的催化效果。研究结果表明,双噁唑啉金属络合物对硝酮的环加成反应有较好的催化作用,表现在反应速度的提高和立体选择性的改变。比较而言,（5）与铜的配合物具有更好的催化作用。使用二氯亚砜作为氯化试剂对双噁唑啉（5）的合成方法进行了合理的改进,使产率由69．7％提高到89％。     

Some technological aspects of methane aromatization (direct and via oxidative coupling)

The investigations on transformation of methane to benzene and naphthalene have been carried out in aim to verify and supplement earlier reported data and on this basis to estimate real industrial perspectives of the CH₄ aromatization concept, the main challenges and barriers. Methane aromatization (direct and via oxidative coupling) has been studied over Mo/HZSM-5 catalyst used both for direct methane dehydroaromatization and for aromatization of methane oxidative coupling (OCM) products. The effects of Mo content in the catalyst, temperature, space velocity, the presence of CO₂, CO, H₂O, C₂H₄, C₂H₆ and their mixtures in the feed have been studied. The effectiveness of the catalyst regeneration in the air was also examined. All results were confronted with the literature data and analyzed from technological point of view. It was confirmed that direct CH₄ aromatization process was characterized by a low CH₄ single-pass conversion, low single-pass yields of the main products (benzene, hydrogen and naphthalene) and a low catalyst stability (rapid catalyst deactivation). Various possible technological schemes were analyzed. It was concluded that real industrial chances of direct methane aromatization or aromatization via OCM would depend largely on the advancement in the cost-effective separation techniques. The methane aromatization concept was also confronted with other methane conversion processes.     

甲醇芳构化技术和经济性分析

介绍了我国BTX芳烃的供需现状、发展趋势和主要生产来源,综述了甲醇芳构化生产技术的研究进展和相关产业化进程。通过经济性分析可知,在高油价背景下,在煤炭产地依托大型煤制甲醇项目建设MTA装置具有一定的竞争力。     

Microbial and Genetic Resources for Cobalamin (Vitamin B12) Biosynthesis: From Ecosystems to Industrial Biotechnology

Many microbial producers of coenzyme B12 family cofactors together with their metabolically interdependent pathways are comprehensively studied and successfully used both in natural ecosystems dominated by auxotrophs, including bacteria and mammals, and in the safe industrial production of vitamin B12. Metabolic reconstruction for genomic and metagenomic data and functional genomics continue to mine the microbial and genetic resources for biosynthesis of the vital vitamin B12. Availability of metabolic engineering techniques and usage of affordable and renewable sources allowed improving bioprocess of vitamins, providing a positive impact on both economics and environment. The commercial production of vitamin B12 is mainly achieved through the use of the two major industrial strains, Propionobacterium shermanii and Pseudomonas denitrificans, that involves about 30 enzymatic steps in the biosynthesis of cobalamin and completely replaces chemical synthesis. However, there are still unresolved issues in cobalamin biosynthesis that need to be elucidated for future bioprocess improvements. In the present work, we review the current state of development and challenges for cobalamin (vitamin B12) biosynthesis, describing the major and novel prospective strains, and the studies of environmental factors and genetic tools effecting on the fermentation process are reported.     

Modeling of the aromatization of gasoline fractions on zeolites under conditions of catalyst deactivation

Models were constructed for the apparent kinetics of base reactions and deactivation of a zeolite catalyst in the process of aromatization of gasoline fractions on zeolites. The adsorbed oligomers were found to exert an inhibitory effect on the reaction and deactivation rates. The industrial processing of gas condensates into motor fuel was mathematically modeled and optimized.     

基于BP神经网络的液化石油气芳构化反应体系的预测模型

将BP神经网络应用于液化石油气芳构化反应体系,建立了该体系在指定反应条件下的神经网络模型,网络的训练结果达到了预设要求,且网络输出结果与试验值能够较好的吻合,所建模型能较准确地预测指定反应条件下该体系的产物分布状况。分析结果可为LPG芳构化技术的进一步开发、生产过程中的产物分布预测和工业过程的模拟提供一些指导。     

正己烷在Zn/HZSM-5上芳构化反应机理的探讨

比较了正己烷在HZSM-5、Al₂O₃和ZnO/Al₂O₃催化剂上的反应性能，探讨了锌含量和水热处理对Zn/HZSM-5芳构化性能的影响。发现B酸是芳构化反应不可缺少的活性中心，Zn-L因其氢解作用促进烃类的活化和脱氢，Al-L酸只是对正己烷有较弱的活化作用。提出了正己烷在Zn/HZSM-5上的芳构化反应机理。     

维生素B6的合成研究进展

维生素B6是一种重要的水溶性维生素,为人体和动物生长所必需,因此被广泛用于医药、食品及饲料添加剂等领域。本文综述了近年来维生素B6的合成研究进展,分别介绍了化学合成方法及微生物法在维生素B6合成中的应用,比较了各法的优缺点,并对研究前景进行了展望。     

活性炭对维生素B3和维生素C吸附与缓释行为研究

研究活性炭吸附维生素B3和维生素C以及在模拟体内环境中的释放过程。探讨了活性炭孔结构对吸附维生素如和维生素C的影响,并对活性炭缓释维生素B3过程进行了数学模拟,初步探讨了吸附和释放机制。实验所用活性炭对维生素B3有较强吸附能力,吸附量达到了94．9mg／g,对维生素C的吸附量仅38．5mg/g。采用活性炭对维生素磁有良好的缓释性能,其整个释放过程符合药物体外释放一级动力学模型为Q=38.25—36．90e^-0.04924t。所用活性炭适于作为缓释维生素B3的载体,而由于维生素C的不稳定性,不适宜使用活性炭缓释。     

B族维生素对B-Z振荡的扰动及其测定

研究了维生素B1、B2和B6对以丙二酸-硫酸铈铵-溴酸钾-硫酸振荡体系的扰动,得出不同浓度的维生素B1、B2和B6能够对该振荡反应曲线的△E(振幅即振荡强度)和△t(振荡周期)产生明显影响;组成浓度、反应温度和自由基对该振荡反应也有影响;得出不同B族维生素的浓度与振荡周期变化值及振幅变化值均有良好的线性关系;得出检测维...     

Estimation on Global Reaction Heat for the Aromatization Process of Liquefied Petroleum Gas

The reaction heat effect analysis for the aromatization process of Liquefied Petroleum Gas (LPG) was completed in this paper. In order to characterize this complex reaction system, one set of independe...