1-[2-(N,N-二甲基氨基)乙基]-5-巯基-1H-四氮唑的制备

介绍了一种1-[2-(N,N-二甲基氨基)乙基]-5-巯基-1H-四氮唑(DMMT)的合成方法。2-(N,N-二甲基氨基)乙胺与二硫化碳反应,制得取代的2-(N,N-二甲基氨基)乙胺基二硫代羧酸;2-(N,N-二甲基氨基)乙胺基二硫代羧酸与氯甲酸乙酯反应,得到2-(N,N-二甲基氨基)乙胺基二硫代羧酸与乙氧基甲酸的二硫代酸酐;二硫代酸酐再经三乙胺碱解,制得2-(N,N-二甲基氨基)乙基异硫氰酸酯;2-(N,N-二甲基氨基)乙基异硫氰酸酯与叠氮化钠反应,制得目标产物1-[2-(N,N-二甲基氨基)乙基]-5-巯基-1H-四氮唑(DMMT)。产物以N,N-二甲基氨基乙胺计,收率为48.0%。采用该法,能够方便地制得1-[2-(N,N-二甲基氨基)乙基]-5-巯基-1H-四氮唑,产物收率高,反应条件温和,操作过程简便,三废少,环境污染小。     

1-甲基-3-三氟甲基-4-吡唑甲酸合成工艺的改进

研究优化合成1-甲基-3-三氟甲基-4-吡唑甲酸并寻找到一条适于工业化生产的工艺路线。以3-(N,N-二甲基氨基)丙烯酸乙酯为起始原料,经过酰化、环化和水解生成目标产物1-甲基-3-三氟甲基-4-吡唑甲酸。以三氟乙酸和二(三氟甲基)碳酸酯为酰氯化剂,三乙胺为缚酸剂,优化反应温度、反应时间和原料配比,一锅法合成2-二甲氨基次甲基-4,4,4-三氟-3-氧代丁酸乙酯;环化时加入适量氢氧化钠调节反应pH值,同时优化反应温度、反应时间和原料配比,提高反应收率和纯度。该路线低成本,产品产率高、纯度高,且操作简单,适于工业化生产。     

2-氯代苯并噻唑的合成

2-氯代苯并噻唑是合成稻田除草剂苯噻酰草胺的中间体之一，在医药合成方面也有应用。其工业品为淡黄色透明液体。其合成方法有两种：一种是用光气作氯化剂，将光气于0℃通入到三氯甲烷、促进剂M、N，N-二甲基氨基甲醛中，在0-10℃反应1h，60℃回流反应8h得     

2-乙氧亚胺基-2-(5-氨基-1,2,4-噻二唑-3-基)乙酸的合成

2-乙氧亚胺基-2-(5-氨基-1,2,4-噻二唑-3-基)乙酸类化合物多用于新型头孢菌素类药物的合成,确定了其合理的工艺路线,以氰基乙酰胺为原料,经肟化、烷基化、三氯氧磷脱水、氨解、溴代、环合、碱性水解得到目标产物。     

N-甲基-2-吡咯醛的合成

杂环系化合物是精细化工产品中一大类重要原料，N-甲基-2-吡咯醛是合成香料、医药和农药的重要中间体。以二氯乙烷为溶剂，经N-甲基吡咯与二甲基甲酰胺、三氯氧磷反应后，再用乙醚萃取制得N-甲基-2-吡咯醛。但这种方法乙醚损耗大，与二氯乙烷分离困难，实际生产时     

关于酰氯化反应对噻霉酮制备工艺影响的研究

研究以2,2-二硫代苯甲酸为原料,用氯化亚砜进行酰氯化反应制得2,2-二硫化二苯甲酰氯,然后通过溴化反应、氨溶反应制得抑菌剂1,2-苯并异噻唑啉-3-酮(BIT)。文章重点研究反应溶剂种类、氯化亚砜用量、反应温度、时间对酰氯化反应收率的影响。结果表明,以二甲苯作为反应溶剂,2,2-二硫化二苯甲酸与氯化亚砜反应的摩尔比为1∶2.1,反应温度控制在60～70℃,反应时间以3小时为宜,2,2二硫代二苯甲酰氯的收率最高可为73.3%。实验表明,酰氯化反应对1,2-苯并异噻唑啉-3-酮制备工艺有很重要的影响。     

氯乙烷法合成N,N-二乙基-3-乙酰氨基苯胺

文章介绍以氯乙烷为原料来代替溴乙烷生产分散紫93的中间体N,N-二乙基-3-乙酰氨基苯胺。通过一系列工艺实验得出:用内衬锆压力釜为反应设备,以氯乙烷代替溴乙烷,与间氨基乙酰苯胺的摩尔比2∶1,反应温度60～65℃,正压反应最高压力不超过1.0MPa,反应时间12～15h,能够制备出达到原来工艺要求的中间体。     

4-硝基-N-甲基-邻苯二甲酰亚胺的合成

N-甲基-邻苯二甲酰亚胺(NMP)主要用于合成4-氨基-NMP，4-氨基-NMP及其衍生物可用于荧光和其它标记研究。它是合成异鲁米诺及其衍生物的重要中间体。     

N,N-二甲氧基乙基间甲苯胺合成工艺研究

研究用2-氯乙基甲醚和间甲苯胺合成N,N-二甲氧基乙基间甲苯胺的工艺条件。采用N,N-二甲基甲酰胺催化合成原料2-氯乙基甲醚。在N,N-二甲氧基乙基间甲苯胺的合成中,使用普通缚酸剂纯碱,采用分批加入原料、补充缚酸剂和分阶段升温的方式,使产品纯度达97%,收率达98%。     

基于2-(1H-咪唑-1-甲基)-1H-苯并咪唑和邻苯二甲酸配体的Co(Ⅱ)配合物的合成及晶体结构

以氮杂环化合物2-(1H-咪唑-1-甲基)-1H-苯并咪唑(imb)为配体,在邻苯二甲酸的存在下,采用常温挥发法制备了一个结构新颖的配合物{[Co(imb)_2(H_2O)_4]_2·2SO_4·CH_3OH·H_2O}n.单晶X射线衍射结果表明,该配合物是双核结构,两种Co(Ⅱ)均为六配位,邻苯二甲酸不参与该配合物的构筑但却是生成该配合物的必要条件。此外,还对该配合物的红外光谱进行了研究。     

3-羟甲基四氢呋喃的合成研究

3-羟甲基四氢呋喃是合成第3代烟碱类杀虫剂呋虫胺和核苷类抗病毒药物喷昔洛韦的关键中间体,但长期以来由于使用大量金属硼氢化物造成生产成本高、安全风险高、废物多等缺点。以γ-丁内酯为原料,经Aldol缩合、硼氢化钠还原两步反应得到3-羟甲基四氢呋喃,总收率为51.9%,该法中间体α-羟甲基-γ-丁内酯只有一个内酯羰基需还原,原料γ-丁内酯和甲醛价廉易得,整个工艺路线适于工业化。     

RP-HPLC法测定左旋苯甘氨酸乙基邓钾盐的含量

建立了测定左旋苯甘氨酸乙基邓钾盐含量的高效液相色谱方法.采用Thermos C18色谱柱,流动相为0.01 mol/L磷酸盐缓冲液(含0.2％(体积分数)三乙胺,85％(体积分数)磷酸,调节pH值为3.0)-乙腈(体积比为5∶95)为流动相,检测波长为220 nm.样品在pH值为2.0条件下水解后,以水解产物苯甘氨酸为...     

嘧菌酯的新合成方法

报道了一种广谱高效杀菌剂嘧菌酯的新合成方法,首先以2-氯苯甲腈与4,6-二羟基嘧啶为原料催化合成4-羟基-6-(2-氰基苯氧基)嘧啶,氯化得到4-氯-6-(2-氰基苯氧基)嘧啶。将4-氯-6-(2-氰基苯氧基)嘧啶与(E)-2-(2-羟基苯基)-3-甲氧基丙烯酸甲酯耦合,生成(E)-2-(2-(6-(2-氰基苯氧基)嘧啶-4-基氧)苯基)-3-甲氧基丙烯酸甲酯(嘧菌酯)。3步总收率为79.8%(以2-氯苯甲腈计),原药质量分数为97%。     

Evaluating the impact of Tax-for-Fee reform (Fei Gai Shui) on water resources and agriculture production in the Zhanghe Irrigation System, China

This article questions the effectiveness and viability of rural Tax-for-Fee reform (Fei Gai Shui) on water resources and agriculture production, taking the Zhanghe Irrigation System of China as a case study example. The Fei Gai Shui reform has been heralded as a possible solution for reducing the excessive fiscal burden on peasants. While the reform may achieve in relieving peasant burdens significantly, the initial impact of Fei Gai Shui on water resources and agricultural production indicate least satisfactory trends. The policy shows significant impact on rice yield and area. It might also have profound impact on cropping pattern but it has yet to be seen. Dependence on local water resources such as ponds show significant increase after Fei Gai Shui as it discouraged farmers to rely on regional water sources. Although the lower regional water use under Fei Gai Shui reduced the water charges paid by farmers, the savings were mostly offset by increasing pumping costs in accessing water from local ponds. Without any adjustments, the Fei Gai Shui is likely to cause serious predicament in agricultural sector. It is visioned that local water resources such as water ponds will continue to play an important role in sustaining agricultural production.     

Exploring the contribution of innovation intermediaries to the new product development (NPD) process: a typology and an empirical study

In the ‘knowledge economy’ upheld by the European Lisbon strategy, knowledge‐intensive services are considered a key driver for innovation and competitiveness. A category of knowledge‐intensive services that has become of utmost importance in the last few decades is new product development (NPD) services, which interconnect distant knowledge domains with the client firms. In addition to NPD service providers, web‐based innovation intermediaries have started to help innovative firms access dispersed bodies of knowledge. Despite the heterogeneity of their characteristics, however, a clear typology of the strategies used by traditional NPD service providers and web‐based intermediaries to interact with their knowledge sources and with their clients is missing. This typology would be very useful for those firms that are willing to collaborate with innovation intermediaries because it could highlight the typologies of NPD problems different intermediaries are apt to address and the managerial challenges that working with them entails. Developing such a classification framework is the main goal of this paper. The typology proposed in this paper suggests that innovation intermediaries should be distinguished based on the following: (1) the way they access their distributed knowledge sources and (2) the way they deliver value to their clients. By combining these two dimensions, four categories of innovation intermediaries are identified, which are named brokers, mediators, collectors and connectors. A multiple case study analysis involving four innovation intermediaries and 12 of their clients is presented in the paper. The analysis provides exploratory insights into (1) the typologies of NPD problems that each class of intermediaries addresses and (2) the managerial challenges that working with each of them entails. These preliminary findings call for further theoretical and empirical research into the complex interaction among innovation intermediaries, their dispersed sources of knowledge and their clients.     

玻璃球负载纳米级SO_4~(2-)/TiO_2固体超强酸的研究

制备了玻璃球负载纳米级SO42-/TiO2固体超强酸,对其催化活性、重复使用效果、失活原因及再生方法进行了研究。该催化剂对乙酸和丁醇的酯化反应在重复使用9次后,反应3 h乙酸的转化率由初次的99.3％变为84.9％,经再生处理,再重复使用6次反应3 h乙酸的转化率由初次的98.0％变为78.3％。催化剂失活原因为活性中心被有机物覆盖以及SO42-的流失。催化产物的气相色谱说明该催化剂选择性好,无副产物生成。     

Fundamental transformations of trust and its drivers: A multi-stage approach of business-to-business relationships

This research tests a multistage model of trust in business-to-business (B2B) relationships. The model contains three forms of trust, each with unique drivers and consequences for buyer–supplier relationships. An exploratory qualitative study (N = 38) and four quantitative studies (N_Total = 616) validate the distinct stages (N1 = 140, N2 = 144, N3 = 152) and provide an overall test of the model (N4 = 180), using structural equation modeling techniques. The results support the proposed modeling of the stages and highlight a positive effect of reputation on calculative trust. Conflict resolution, communication, and sympathy positively affect cognitive trust. However, shared values do not significantly drive affective trust. Interdependence also exists among the three trust forms, both directly and indirectly. That is, calculative trust does not affect investments in relationship or confidential communication, but cognitive trust influences these constructs indirectly, through the mediation of affective trust. Affective trust also leads directly to greater investments in relationship and generates additional confidential communication.     

“If I was going to design a chair,the last thing I would look at is a chair”: product analysis and the causes of fixation in students’ design work 11–16 years

Creativity is acknowledged to be important for economic growth and as an everyday life-skill, however several influential reports have suggested that education could do more to harness creative talent. Creative cognition literature suggests the lack of creativity is at least partly the result of ‘fixation’ (difficulty in generating novel ideas due to imagination being ‘structured’ by existing knowledge). This paper focuses on the secondary (students aged 11–16 years) design and technology (D&T) context in the UK. Here we examine whether teacher practice can contribute to fixation by focusing on one specific facet of teacher practice in D&T; the use of product analysis to inform the generation of creative design ideas. Data is drawn from the preliminary phase of a research and intervention project from interviews with D&T teachers (N = 14), students (N = 126) and lesson observations (N = 10) and an analysis of documents and student work. Product analysis is widely used at different points in design projects but, as is shown, in all cases current practice can lead to fixation, as thinking is constrained down specific paths and tasks are at best at procedural rather than comprehension level. The implications of these findings and tentative ways forward for practitioners are discussed.