降龙涎香醚的合成进展

降龙涎香醚是公认的天然龙涎香最好的代用品之一,具有强烈的、特殊的龙涎香香气,对其合成方法的研究一直是化学工作者们的研究热点.本文对其合成方法的研究进行了综述.     

盐酸氯普鲁卡因的化学合成研究综述

盐酸氯普鲁卡因是从盐酸普鲁卡因发展而来的高效局麻药,临床用于浸润麻醉、神经阻滞麻醉、骶管和硬膜外麻醉等。对其合成方法的研究一直是化学工作者们的科研热点。本文对其合成方法的研究进行了综述。     

盐酸普萘洛尔的化学合成进展

盐酸普萘洛尔是一种重要的β受体阻断剂，临床上用于治疗高血压、心绞痛和心律失常等病症的药物，疗效良好，对其合成方法的研究一直是化学工作者们的科研热点，本文对其合成方法的研究进行了综述。     

碳酸二甲酯实验室开发的合成方法

综述了碳酸二甲酯(DMC)实验室开发的合成方法：甲醇气相氧化羰基化直接合成法、甲酵和二氧化碳直接合成法、尿素和甲醇合成法和甲醇电羰基化合成法。对甲醇和二氧化碳合成法的催化剂的研究进行了详细的总结，指出甲醇和二氧化碳直接合成法是具有理论和现实意义，对其开发新的催化体系，使其工业化，是目前研究的热点。并结合目前离子液体研究现状指出将离子液体引入到DMC的合成路线中，是今后研究发展的趋势。     

2-甲基-4-甲氧基二苯胺的合成概述

综述了DPA的合成方法,特别是近年来合成DPA的新方法、新技术,并对其优缺点进行了讨论,为以后DPA合成研究以及工业化提供依据。     

生物催化技术在手性化合物合成中的应用

生物催化的手性合成是当今手性合成方法研究的热点和发展方向。本文综述了生物催化技术在手性化合物合成中的应用,并对其应用前景进行展望。     

咖啡呋喃的研究进展

咖啡呋喃是一种香势强的呋喃环含硫香料,对于咖啡呋喃的研究,起步于分析技术的20世纪60年代,发展于20世纪70年代,鉴于其源于自然界的提取量根本满足不了市场的需求以及其合成难度,科学家们一直在探索高效的合成方法。至今国内外已有几种不同的合成方法。对近年来国内外咖啡呋喃合成方法的研究进展进行综述,以期对厂家的生产以及进一步的研究提供详细的参考。     

环己基苯的合成工艺研究综述

环己基苯,又称为苯基环己烷,是一种重要的化工中间体,也是一种高沸点溶剂。环己基苯具有十分广泛的应用,使其成为具有极高的附加价值精细化工产品。因此研究环己基苯的合成工艺,获得高收率、高纯度的环己基苯,具有十分可观的经济价值,它的合成工艺受到人们的广泛关注。介绍其几种主要的合成方法,对其合成方法进行评述,并对环己基苯合成体系进行展望。     

国外4—甲基咪唑的合成及提纯技术

4-甲基咪唑是重要的有机合成中间体,可用于合成多种药品和化学品,也可用作催化剂和树脂硬化剂等。国外对其合成及应用都有大量研究,而国内却少见报导。为此本人检索了大量文献,对其合成及提纯方法进行了综述,希望对国内的研究与开发有所帮助。现将文献报道的有关其合成和提纯技术综述如下:     

米索前列醇中间体环戊烯酮的合成工艺研究进展

环戊烯酮是合成米索前列醇及其他一些前列腺素药物的关键中间体,对其合成工艺的研究具有重要的意义。本文从不同的起始原料出发概述了环戊烯酮的合成方法。     

顺式二氢茉莉酮酸甲酯的合成技术改进

以普通二氢茉莉酮酸甲酯为初始原料,N-溴代丁二酰亚胺作为溴代试剂,三乙胺为脱溴试剂,制得脱氢二氢茉莉酮酸甲酯;以Pd/C作催化剂,环己烷作溶剂,在温度为20℃,氢气压力为0.4 MPa下,脱氢二氢茉莉酮酸甲酯经催化氢化合成顺式二氢茉莉酮酸甲酯,经精馏得到的最终产品中顺式产品质量分数为35%。     

二氢茉莉酮酸甲酯生产工艺的研究

二氢茉莉酮酸甲酯是一种深受人们喜爱的茉莉香型的重要香原料。本文以环戊酮和戊醛为原料在碱催化下 ,以缩合和异构化反应合成了 2 -戊基环戊烯酮。 2 -戊基环戊烯酮再与丙二酸二甲酯缩合 ,脱羧得二氢茉莉酮酸甲酯 ,并且进行了中试放大 ,确定了最佳工艺条件     

Effects of octadecanoid metabolites and inhibitors on induced nicotine accumulation inNicotiana sylvestris

We examined the effects of inhibitors of the octadecanoid pathway (n-propyl gallate, acetosalicylic acid, salicylhydroxamic acid, methyl salicylate, and antipyrine) on wound- and jasmonate-induced nicotine accumulation and compared the nicotine-inducing ability of exogeneous additions of linolenic acid (18:3) and its methyl ester, linoleic acid (18:2), abscisic acid, traumatic acid, and methyl dihydrojasmonate to the nicotine-inducing ability of exogenous additions of methyl jasmonate (MJ). The first four of these inhibitors significantly reduced wound-induced nicotine accumulation when applied in a lanolin paste to wounded tissues immediately after wounding at concentrations of 89–90µg/plant. When methyl salicylate and propyl gallate were mixed individually with MJ, neither inhibited MJ-induced nicotine synthesis, which suggests that the inhibitors block jasmonate synthesis or release from stored pools and not its effects. Linolenic acid or its methyl ester applied to undamaged plants or damaged plants (to either damaged or undamaged leaves) or to the roots of hydroponically growing plants did not induce nicotine accumulation or increase nicotine accumulation above levels found in damaged plants. Similarly, traumatic acid, linoleic acid, and abscisic acid did not induce nicotine accumulations. Methyl dihydrojasmonate, which is biosynthetically derived from linoleic acid, had 12–56% of the nicotine-inducing acitivity of MJ when added to the roots of hydroponically grown plants. The signal transduction pathway mediating wound-induced nicotine production therefore shares many features of the pathway eliciting wound-induced proteinase inhibitor production but differs in not being regulated at the lipase step in jasmonic acid production and not being responsive to abscisic acid.     

二氢茉莉酮酸甲酯合成新方法

以正戊醛和环戊酮为原料,在酸性催化剂催化下进行缩合,直接得到２－戊基环戊烯酮,收率达７８％。２－戊基环戊烯酮再与丙二酸二甲酯缩合,脱羧得到二氢茉莉酮酸甲酯。三步反应总收率５９％。     

2—丁烯氢甲酰化制香料醛

正戊醛是合成香料双氢茉莉酮酸甲酯的重要原料。目前为止,大多数厂家均采用钴、铑催化剂进行羰基合成,但由于我国铑资源短缺,而钴催化法则不大适合用来合成醛。文中介绍了以2-丁烯为原料,用铁钴簇催化剂羰基合成法制正戊醛的新方法,与用贵金属铑、钴催化剂法相比,可降低产品成本。     

二氢茉莉酮酸甲酯的合成工艺条件研究

用正戊醛和环戊酮为原料,合成二氢茉莉酮酸甲酯。通过元素分析、GCMS、IR、HNMR等手段对产物进行了定性测试,结果表明,所合成产物是二氢莱莉酮酸甲酯。同时还对正戊醛的加入方式、碱浓度、反应温度、原料配比对收率和选择性的影响进行了研究。结果表明采用滴加方式加入正戊醛,温度为80℃,碱溶液为1%,原料配比为1∶1.5时对反应最有利。     

二氢茉莉酮酸甲酯的合成研究

以环戊酮与正戊醛为原料,经缩合、异构化反应、Michael加成、高温脱羧四步反应合成了香料化合物二氢茉莉酮酸甲酯,总收率达61%,产品经元素分析、核磁共振、红外光谱、质谱表征。此合成工艺步骤短、收率高、原料易得,已成功应用于工业化生产。     

由有机卤化锌试剂合成二氢茉莉酮酸甲酯的新方法

探讨了以2-戊基-2-环戊烯酮为原料,以乙酰丙酮镍和三乙胺为催化剂以及在Me,SiCl作用下,烯丙基溴化锌与2-戊基-2-环戊烯酮的Michael加成反应,合成了2-戊基-3-烯丙基环戊酮,产率达74%.然后2-戊基-3-烯丙基环戊酮经过三氯化钌/高碘酸钠氧化、亚硫酰氯/甲醇酯化,得标题化合物.在适宜的条件下,3步反应总收率59%.     

Structural Requirements of Jasmonates and Mimics for Nicotine Induction inNicotiana sylvestris

Jasmonic acid (JA) is strongly implicated in the long-distance signal transduction cascade increasing nicotine synthesis in the roots of plants after leaf wounding. In order to explore the structural requirements of the inducing signal, we examined jasmonates, mimics, and a biosynthetic precursor for nicotine-inducing activity (NIA). We examine the importance of the keto group on the five-membered ring and the double bond in then-pentenyl chain by comparing the NIA of methyl jasmonate (MJ) with that of cucurbic acid, 1,3-dithiolane-MJ, 1,3-dioxolane-MJ, methyl dihydrojasmonate (DHMJ), 1,3-dioxolane-DHMJ, 1-oxo-indan-4-carboxylic acid ILE-methyl ester, and 1-hydroxyl-indan-4-carboxylic acid ILE-methyl ester. We found that: 1,3-dioxolane MJ, cucurbic acid, and 1,3-dioxolane DHMJ were less active than MJ and that the isoleucine (ILE) conjugates of 1-oxo- and l-hydroxyindanon-4-carboxylic acid had the same NIA as MJ. The activities of these indanon amino acid conjugates may be due to the structural similarity of their keto or hydroxyl groups on the five-membered ring to MJ or to the keto-enolized MJ. These results support the hypothesis that the enolization of the keto group during or prior to its interaction with the putative JA receptor is required for activity. We explore the importance of the esterification of the carboxyl functional group by comparing the NIAs of cucurbic acid and cucurbic acid methyl ester, l-oxo-indan-4-carboxylic acid, 1-oxo-indan-4-carboxylic acid methyl ester, and l-oxo-indan-4-carboxylic acid ILE-methyl ester. In all cases, the esters were more active than the free acids. We compared the NIA of MJ of different epimeric composition (8% and 20% 3R,7S-MJ); 12-oxophytodienoic acid (12-oxo-PDA) methyl ester, an important precursor of JA; and coronatine (a well-known phytotoxin and putative structural mimic of 12-oxo-PDA).We found that: (1) the epimeric composition of MJ did not affect its NIA; (2) 12-oxo-PDA methyl ester had lower NIA than MJ; and (3) coronatine significantly inhibited plant growth but did not increase nicotine biosynthesis. In summary, JA, rather than its biosynthetic precursor, 12-oxo-PDA, is likely the endogenous signal inNicotiana sylvestris, and the keto functional group on the five-membered ring and the double bond in then-pentenyl side chain are crucial components of JA for NIA.