3-羧基-5-氟苯基硼酸的合成工艺研究

3-羧基-5-氟苯基硼酸是一种重要的有机合成中间体,可通过suzuki芳基偶联反应合成多烯烃、苯乙烯和联苯的衍生物,从而应用于众多天然产物、有机材料的合成中。本文以5-氟-3-溴甲苯为原料,利用两步反应合成目标产物的合成工艺:1利用有机锂试剂法合成3-氟-5-甲基苯硼酸;2将3-氟-5-甲基苯硼酸经过氧化反应合成目标产物,总产率为75.5%。本合成路线操作简单,原料的价格低,符合工业化生产的要求,可以进行工业化生产。     

生物合成天然手性γ-癸内酯

香味物质在食品生产中起着重要的作用 ,近年来人们由于健康的原因而倾向于使用天然产品 ,对天然香料的需求也大大增加了。由于合成香料与天然香料的价格相差较大 ,这使得寻找其他生产天然香味物质的方法成为必须。本文介绍了近年来采用生物法合成天然手性γ 癸内酯的研究进展。     

催化脱氢合成(-)-4-(1,5-二甲基-4-己烯)-2-甲基苯酚

研究了催化脱氢法合成(-)-4-(1,5-二甲基-4-己烯)-2-甲基苯酚的工艺。笔者以PdCl2为脱氢试剂,考察了反应溶剂、温度、时间和PdCl2用量对合成该天然产物的影响。在优化的工艺条件下,(-)-4-(1,5-二甲基-4-己烯)-2-甲基苯酚的收率可达到82%。     

7-(2-甲基-3-丁炔-2-氧基)-香豆素的合成研究

分别考察了常规条件下和微波合成条件下,碘催化法合成7-(2-甲基-3-丁炔-2-氧基)-香豆素的研究.实验结果表明,微波合成法不仅大大缩短了反应时间,还节省了昂贵原料3-氯-3-甲基-1-丁炔的用量,是合成该产物较优的合成方法.此外,还对比考察了Mitsunobu成醚法与碘催化法合成目标产物,并对二者的反应历程进行了探讨,对DCC法合成进行了尝试.     

α-酮酰胺化合物合成研究进展

α-酮酰胺化合物是一类具有良好生物活性的胺类化合物,广泛存在于天然产物中,因此倍受科研工作者关注,并且被用于药物分子结构设计中。本文综述了近些年α-酮酰胺化合物物的合成研究进展,并对未来的研究方向进行了展望。     

N-(4-羟基-3-甲氧基苄基)-癸酰胺的合成及其生理活性

以香草醛、正癸酸、SOCl2为原料,3步反应合成了辣椒碱类物质——N-(4-羟基-3-甲氧基苄基)-癸酰胺,其结构经IR、1HNMR、13CNMR和元素分析确认。对比研究目标产物与天然辣椒碱生理活性:两物质辣度相近,目标产物辣度仅比天然辣椒碱低0.4%;目标产物镇痛活性优于天然辣椒碱30%;两物质抗菌活性基本相同,强于苯甲酸钠;驱避老鼠活性相似;两物质毒性级别均为3级(低毒)。因此,合成辣椒碱——N-(4-羟基-3-甲氧基苄基)-癸酰胺在上述生理活性上有替代天然辣椒碱的使用价值。     

β-卡巴林类化合物的合成研究进展

卡巴林类化合物是一种吲哚类生物碱,其结构中含有三环吡啶并吲哚的母核,广泛存在于天然产物中。其类型主要有4种：α-卡巴林、β-卡巴林、γ-卡巴林、δ-卡巴林。其中,β-卡巴林类化合物因其具有广泛的药理活性,如：抗肿瘤、抗阿尔茨海默病等,得到了深入的研究。综述了β-卡巴林类化合物的合成研究进展,为寻找高效、便捷、反应条件温和的β-卡巴林类化合物合成方法提供了参考。     

孕甾-16-烯-3S,20S-二醇二乙酸酯的高效合成及其钯催化反应的再研究

提供了一种将剑麻皂甙元降解产物孕甾三醇转化为孕甾-16-烯-3S,20S-二醇二乙酸酯(Ⅱ)的高效合成方法,并重新考察了其钯催化反应。研究发现亲核取代反应和消除反应互相竞争,在醋酸钯催化下,C-20亲核取代产物Ⅲ为主产物,而在四(三苯基膦)合钯催化下,则主要生成C-20消除产物(Ⅴ)。这些结果不仅为甾体药物和生物活性天然甾体化合物合成提供了新的合成中间体,也为进一步合理利用剑麻皂甙元资源提供了新思路。     

新型4-羟基香豆素衍生物的合成与表征

香豆素是自然界天然产物中一类十分重要的有机化合物。以4-羟基香豆素为原料,采用微波合成法"一锅煮"法,合成了系列新型香豆素衍生物,所有产物进行了IR、MS、1HNMR结构表征,其中部分产物为首次合成。为此类抗凝血药物的研究提供了理论技术支持。     

合成蔗糖-6-酯的研究进展

氯蔗糖是迄今为止人类开发的一种最完美的强力甜味剂,蔗糖-6-酯是制备三氯蔗糖的重要中间体,蔗糖-6-酯的制备是合成三氯蔗糖的关键技术之一.如何提高蔗糖-6-酯的纯度和收率一直是备受关注的问题,文章介绍了蔗糖-6-酯的三类合成方法:直接酯化法,二丁基氧化锡法和酶法,综述了其研究进展;通过对每一类方法的比较,指出了它们各自的优缺点:直接酯化法一步反应、操作简单,但产物难以提纯、收率低,成本相对较高;二丁基氧化锡法反应步骤稍多,但操作简单、产物易于分离提纯、收率高,利于工业化;酶法反应路线短,无有机溶剂、污染小,但酶的活性较低、反应周期长、费用高,产物分离提纯较难、收率低.     

Recent advances in the Biginelli dihydropyrimidine synthesis. New tricks from an old dog

In 1893, P. Biginelli reported the synthesis of functionalized 3, 4-dihydropyrimidin-2(1H)-ones (DHPMs) via three-component condensation reaction of an aromatic aldehyde, urea, and ethyl acetoacetate. In the past decade, this long-neglected multicomponent reaction has experienced a remarkable revival, mainly due to the interesting pharmacological properties associated with this dihydropyrimidine scaffold. In this Account, we highlight recent developments in the Biginelli reaction in areas such as solid-phase synthesis, combinatorial chemistry, and natural product synthesis.     

Heteropoly acid catalyzed synthesis of 3,4-dihydropyrimidin-2(1H)-ones

Simple and improved conditions have been found to carry out the Biginelli reaction for the synthesis of 3,4-dihydropyrimidin-2(1H)-one derivatives. This synthesis was performed using 11-molybdo-1-vanadophosphoric acid (H₄PMo₁₁VO₄₀) in ethanol solution. Compared with the classical Biginelli reaction conditions, this new method has the advantage of excellent yields (85–95%).     

Synthesis of Dihydropyrimidinones Using Large Pore Zeolites

Abstract  

A series of dihydropyrimidin-2(1H)-one (DHPM) belongs to one of the important class of therapeutic and pharmacological active compound, were synthesized through the multicomponent reactions (MCRs) of aldehydes, ethyl acetoacetate and urea, followed by the heterogeneous catalyzed Biginelli reaction. In the present endeavour, medium (ZSM-5) and large pore zeolites (Y, BEA and MOR) as well as dealuminated zeolites BEA, were studied as catalysts. An excellent activity for DHPMs synthesis is achieved by optimizing accessibility of the reactants to the active sites and the surface polarity of zeolite catalysts. Moreover, the mechanism of Biginelli reaction was studied by means of GAUSSVIEW energy calculations of adsorbed acylimine intermediate on zeolite by using the density functional method (DFT).     

CuI as reusable catalyst for the Biginelli reaction

An improved protocol for the Biginelli reaction using CuI as a reusable catalyst is described. The synthesis of 3,4-dihydropyrimidin-2(1H)-ones was achieved in acetonitrile, water and under solvent-free condition. After separation of product from the reaction mixture, the mother liquor (acetonitrile or water) containing the catalyst was reused two times without any loss of activity.     

NH4Cl催化微波照射合成3,4-二氢嘧啶-2-酮衍生物

经典的Biginelli反应用HCl作催化剂,通常产率较低(20%～50%).本文用NH4Cl作为催化剂,反应中用元水乙醇作溶剂,在微波辐射下反应.此改进方法具有催化剂廉价易得、反应时间短、收率高、操作简便等优点.本文所制得的9种3,4-二氢嘧啶-2-酮类化合物,收率较经典的Biginelli反应收率有较大的提高.该方法的使用为3,4-二氢嘧啶-2-酮衍生物的制备提供了一条方便、快捷、有效的合成方法.     

Trichloroisocyanuric acid,a new and efficient catalyst for the synthesis of dihydropyrimidinones

An efficient three-component synthesis of 3,4-dihydropyrimidinones using trichloroisocyanuric acid (TCCA) as a mild, homogeneous and neutral catalyst for Biginelli reaction in ethanol or DMF under reflux condition and microwave irradiation is described. Yields are excellent in either of the two conditions.     

Recyclable Amberlyst-70 as a Catalyst for Biginelli Reaction: An Efficient One-Pot Green Protocol for the Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones

An environmentally benign aqueous protocol for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones using Amberlyst-70 as a recyclable catalyst has been developed. The use of resinous, nontoxic, thermally stable and inexpensive Amberlyst-70, as a recyclable heterogeneous catalyst, makes the process simple with negligible chemical waste. Thus renders this method an environmentally acceptable synthetic tool for Biginelli reaction.     

HBF4-catalyzed Biginelli reaction: One-pot synthesis of dihydropyrimidin-2(1H)-ones under solvent-free conditions

An efficient synthesis of dihydropyrimidinones from the aldehyde, 1,3-dicarbonyl compound and urea (thiourea) under solvent-free conditions, using fluoroboric acid as the catalyst, is described. Compared with the classical Biginelli reaction conditions, this new protocol has the advantage of high yields, short reaction time and simplicity in the experimental procedure.     

Biginelli反应的研究新进展

1893年,意大利化学家Pietro.Biginelli首次利用苯甲醛、乙酰乙酸乙酯和尿素三种原料＂一锅法＂合成了3,4-二氢嘧啶-2（1H）-酮（DHPMS）。后来,经过大量研究证明该类化合物具有良好的药理活性和生物反应活性,是抗癌药物及海洋生物碱的重要中间体。因此本文对Biginelli衍生化反应的机理和Biginelli反应的影响因素两个方面进行了详细阐述.     

瑞舒伐他汀中间体的合成工艺改进

采用B iginelli嘧啶酮缩合反应,以4-氟苯甲醛、异丁酰乙酸甲脂和硫脲为原料,在质子酸存在下经缩合、甲基化、氧化、亲核取代、还原和氧化反应,合成了降血脂药物瑞舒伐他汀(Rosuvastatin)的中间体嘧啶醛化合物(Ⅶ),总收率为32.5%,与H irai K所申请的专利(US 5 260 440,1993)的方法相比,不仅缩短了反应步骤,而且收率提高了14.5%。化合物的结构经1HNMR,IR和MS进行了确证。