2,3,4-三氟硝基苯合成工艺新进展

2,3,4-三氟硝基苯是合成氟喹诺酮药物的重要中间体.介绍了4条工艺合成路线,按起始原料分,它们是:1)2,6-二氯苯胺法;2)2,6-硝基苯法;3)2,6-溴苯胺法,4是最近提出的新工艺技术,即以1,2,3-三氯苯作原料,通过硝化、氟化制得到产品.产品纯度达99%,收率为60%,这是一条较有发展前景的工业化合成路线,值得引起关注.     

2-氯-5-三氟甲基吡啶合成的研究进展

2-氯-5-三氟甲基吡啶是许多药物的关键中间体.因此,对2-氯-5-三氟甲基吡啶的多种合成方法进行了系统的研究及分析.结果表明,以氯化苄为起始原料的合成工艺安全可靠,生产成本低,效率高,污染少,容易工业化等优点,是一条经济可行的路线.     

2-氯烟酸合成研究进展和应用前景

介绍了近年合成2-氯烟酸工艺路线新进展,对其中两种合成路线作了详细比较。如以3-氰基吡啶为起始原料,先经乙酰丙酮酸钼催化氧化得到烟酸酰胺N-氧化物后,在苯磷酰二氯作催化剂,以三氯氧磷氯化后,经水解得到2-氯烟酸,总收率95．0％。另外一种工艺路线是以烟酸为原料,以过氧化氢催化氧化为N-氧化物,然后以POCl,作氯化剂,经水解得2-氯烟酸,总收率为87．4％。其后介绍了2-氯烟酸在农药和医药方面的应用。     

新型含氟液晶的合成与性能研究

2-氟-4-羟基苯甲酸在液晶材料的合成中具有重要作用和更多的优势。以3-氟-4-氰基苯酚为原料制备出了2-氟-4-羟基苯甲酸,经过醚化和酯化后合成出了一系列新型含氟液晶单体,采用红外光谱（FT-IR）、核磁共振（1H-NMR）、偏光显微镜（POM）、X射线衍射（WXRD）与差示扫描量热分析（DSC）等测试手段,对单体的结构和性能进行了表征。结果表明此类单体为热致互变液晶,并具有更宽的液晶温度区间和更好的液晶性能。     

2-氯-5-甲基吡啶的合成及应用研究

2-氯-5-甲基吡啶是生产吡虫啉、吡氟禾草灵等高效、低毒、低残留新农药的关键中间体。综述了2-氯-5-甲基吡啶的7种主要合成方法:3-甲基吡啶氧化法、3-甲基吡啶一步氯化法、重氮化法、熔融盐法、苄胺环合法、环化法及吡啶酮法,并简单介绍了2-氯-5-甲基吡啶在农药和生物化学品合成中的应用、研发现状及发展趋势。     

4''''-(4-正丙基环己基)苯甲酸(PCA)的合成研究

本文以4-正丙基环己醇和溴苯为原料,经五步合成液晶中间体PCA.对反应路线进行了摸索,对反应工艺条件进行了研究,找到了最佳工艺条件.     

7-苯乙酰氨基-3-乙烯基头孢烷酸对甲氧苄酯的合成工艺研究

选用7-苯乙酰氨基-3-氯甲基头孢烷酸对甲氧苄酯(GCLE)为原料制备了7-苯乙酰氨基-3-乙烯基头孢烷酸对甲氧苄酯。GCLE与卤化物、三苯基膦反应生成3位膦盐,在碱性条件下得到Wittig试剂(膦叶立德),再与甲醛反应生成7-苯乙酰氨基-3-乙烯基头孢烷酸对甲氧苄酯。实验结果采用正交表进行分析,结果表明,选用KI为卤化剂,K2CO3为碱性介质,n(甲醛)∶n(GCLE)为1∶10,溶剂为丙酮/CH2Cl2时,所得产物收率较高。     

AlPW/SiO2的制备及其在苊与苯甲酸的酰基化反应中的催化性能

采用浸渍法制备了二氧化硅(SiO2)负载磷钨酸铝(AlPW)催化剂(AlPW/SiO2),通过BET、XRD、FT IR和NH3-TPD等方法对AlPW/SiO2催化剂进行了表征。将所制备的AlPW/SiO2用于催化苊与苯甲酸的Friedel-Crafts酰基化反应,在温和条件下合成了5-苯甲酰苊,并考察了AlPW/SiO2的催化性能。实验结果表明:当磷钨酸铝负载量为40%时,AlPW/SiO2达到最佳催化活性,目标产物5-苯甲酰苊在最佳反应条件下的收率和选择性分别可达56.9%和90.4%。5次重复实验结果显示,AlPW/SiO2催化剂重复使用效果良好,是一种高效、绿色环保、低成本的Friedel-Crafts酰基化反应新型催化剂。     

（R）-乙基-6-[2-（叠氮甲基）吗啉基]己酸酯的合成工艺

以R-苄基缩水甘油醚、6-溴己酸乙酯为原料,经环合、氨基保护、催化氢化、酰化、叠氮取代、脱保护、烃化反应,成功得到了（R）-乙基-6-[2-（叠氮甲基）吗啉基]己酸酯。反应条件温和,操作简单。产物经过核磁共振、质谱确认。     

京津冀地区产业结构的特征梳理与未来展望——基于偏离-份额分析

本文梳理和总结了京津冀地区的产业结构特点和重叠性问题,运用偏离-份额分析法测度了京津冀地区的产业结构和竞争力对经济增长偏差的贡献率,对比分析了北京、天津和河北在产业发展中的优势与劣势,最后根据研究结果提出未来展望。     

氟喹诺酮药物中间体合成研究进展

介绍了合成喹诺酮药物-些重要中间体所取得的新进展,这些中间体包括：2,3,4-三氟～4-硝基苯、2,4-二氯-5-氟苯甲酸、4-丁酰氯、2,6-二氯-5-氟烟酰乙酸乙酯、2,4-二氯-5-氟苯乙酮、2,4-二氯氟苯等。另外,对某些合成方法的改进作了较详细叙述,如：2,4-二氯氟苯、2,4-二氯-5-氟苯甲酸等。如其中以1,2,3-三氯苯为起始原料,经硝化、氟化两步反应制得的1,2,3-三氟-硝基苯产品质量分数大于99％,收率达60％。     

Inflation targeting rules and welfare in an asymmetric currency area

This paper studies the effect on monetary policy of differing degrees of competition and differing degrees of nominal rigidity between the members of a monetary union. In particular, we assess the welfare loss brought about by the use of a simple interest rate rule that does not take into account such structural differences. Our results show that, ceteris paribus, to maximize welfare the central bank should react more strongly to inflation pressure generated by the more competitive economies. Our work extends the results of Benigno [Benigno, P., 2004. Optimal monetary policy in a currency area. Journal of International Economics 63, 293-320] by showing that, if the degree of competition differs between countries, the optimal rule could involve placing a greater weight on the more “flexible” countries. Our study suggests that the size of the welfare losses generated by failure to take account of these asymmetries depends crucially on the actual combination of the various asymmetries. As a consequence, we show that, if the optimal weights are chosen under incomplete information regarding the extent and type of asymmetries, the resulting level of welfare could be lower than that produced by the symmetric rule.     

纳米TiO2光催化剂的制备与应用研究进展

本文综述了国内外对纳米TiO2液相制备方法的研究进展,阐述了液相沉淀法、溶胶-凝胶法、醇盐水解法、水热法等液相制备法,并讨论了纳米TiO2在气体净化、表面自清洁、污水处理、杀菌等方面的应用.     

Co–evolution of Industry Structure,Technology and Supporting Institutions,and the Making of Comparative Advantage

In recent years,a considerable body of research has been established on the co–evolution of technology and industry structure, from the time that the technology is young to the time when it is mature· A somewhat smaller body of research has been established on how private and public institutions, and public programs and policies co-evolved with a technology and industry· It is proposed here that nations differ in their pace and pattern of institutional response to the birth and development of an industry, and that the locus of comparative advantage is largely determined by these different kinds of national response.     

The integrated use of social media,digital, and traditional communication tools in the B2B sales process of international SMEs

Social media and digital tools are gradually changing the way firms market themselves. Understanding how these communication tools are used by sales functions within business-to-business (B2B) markets could clarify the dynamics underpinning the sales process in an increasingly technology-mediated world. This paper explores how social media, digital, and traditional sales communication tools are leveraged during the three main phases of the B2B sales process within international SMEs.The article’s grounded-theory approach illustrates that social media can be particularly helpful in engaging international prospects. Digital communication tools seem to be most prevalent in the persuasion phase, whereas more traditional communication tools still prevail in customer relationship management. However, there seem to be some important potential boundary conditions, including relationship culture, location proximity, technology innovation/resources, and strategic importance of the customer that affect the way international SMEs use different communication tools during a sales process. We develop a framework for understanding the B2B sales process flow with sales communication tools included for international SMEs.     

Agency and Control Problems in US Corporations: The Case of Energy-efficient Investment Projects

Private sector corporations in the United States fall short of their potential to increase shareholders'1 wealth in a number of ways. One example is the failure to undertake profitable energy conservation investments. Explanations of this phenomenon include agency and moral hazard problems, imperfect information and incentives, myopia, and X-inefficiency. Data from a survey conducted by the US Environmental Protection Agency and from interviews with corporate executives are used to explore these hypotheses. Good overall corporate performance is found to be associated with longer internal payback requirements for energy investments. Suggestions for improving corporate decision-making in this area are proposed.     

Interest rates and the recent weakness in M2: An extension to the P model of inflation

A model of changes in the deflator for nondurables and services consumption expenditures is estimated simultaneously with the error-correction model of M2 growth described in Koenig (1996). The inflation forecasts generated by the joint model have marginal predictive power for changes in the GDP deflator and exhibit none of the systematic bias which has plagued the original formulation in recent years. Output-market slack is of little use in predicting changes in the consumption deflator, but there is evidence of a speed effect.     

Ownership concentration,separation of voting rights from cash flow rights,and earnings management: an empirical study in Canada

Drawing from models of Jones (1991) and Kothari, Leone, and Wasley (2005), this study examines the relationship between Canadian corporate ownership structure and earnings management from 1995 to 1999. There is evidence of a nonmonotonic relationship. The concentration of voting and cash flow rights with the ultimate owner first increases earnings management, but as the level of ownership concentration increases, earnings management decreases. There is also a positive correlation between earnings management and voting and cash flow rights divergence. This is particularly evident when the gap between voting and cash flow rights is high. Copyright © 2008 ASAC. Published by John Wiley & Sons, Ltd.