合成二氢茉莉酮的一种新方法

茉莉酮和二氢茉莉酮是一类名贵香料,研究这类化合物的合成方法一直是人们感兴趣的问题。已有许多报道,其中包括甲基乙烯基酮和庚醛或1-硝基庚烷进行Michael加成得到1,4-二酮进行分子内缩合成的二氢茉莉酮。本文报道一种从甲基乙烯基酮和1-己烯经过2-己基-5-甲基-1,2-氧硼杂环戊烷中间     

等效剂在合成中的应用研究：Ⅵ.合成二氢茉莉酮的新途径

茉莉酮和二氢茉莉酮是一类名贵的香料,此类化合物的合成一直是人们所关注的问题。已有许多报道,其中包括庚醛、1-硝基庚烷与甲基乙烯基酮进行Michael加成和以硝代甘缩酮与庚醛进行硝-醛缩合制得1,4-二酮,再进行分子内缩合为二氢茉莉酮。这些合成方法,有的对反应条件要求较苛刻,不易操作,有的则反应步骤较多,收率低。最近,白俊才等以甲基乙烯基酮和1-己烯为原料,合成了二氢茉莉酮,此法虽然新颖,但氧硼杂环己烷中间体     

茉莉酮及二氢茉莉酮的新合成

以3-硅基环戊-2-烯酮为原料,用连串的烷基共轭加成-亲核烷基化方法,可方便地制得茉莉酮及二氢茉莉酮.     

聚醚酮醚酮酮/含萘环聚醚酮醚酮酮无规共聚物的合成与性能

在无水AlCl3及N－甲基吡咯烷酮（NMP）存在下，以4,4′-二（α－萘氧基）二苯酮（DNBP）作为第三单体，将其与4，4′－二苯氧基二苯酮（DPBP）和对苯二甲酰氯（TPC）在1，2－二氯乙烷（DCE）中进行低温溶液共缩聚反应，合成了一系列聚醚酮醚酮酮／含萘环聚醚酮酮醚酮酮无规共聚物，用IR、DSC、TG及WAXD等方法对其结构和性能进行了表征与测试。研究结果表明共聚物的玻璃化转变温度（Tg)要比纯PEKEKK的高，而其熔融温度（Tm)和结晶度（Xc)则随共聚物中含萘环PEKEKK结构单元含量的增加而逐渐降低。共聚物具有优异的耐热性能及抗腐蚀性能。     

二氢茉莉酮酸甲酯的合成研究

二氢茉莉酮酸甲酯是非常重要的人工合成香料,其合成方法是有机合成工作者研究的重点。以2-戊基-2-环戊烯-1-酮为原料,经Michael加成/脱甲氧羰基合成二氢茉莉酮酸甲酯是常用的合成路线。本文着重对脱甲氧羰基步骤进行了优化。尝试加入卤盐以降低该反应温度,发现盐的加入导致逆Michael加成产物的生成,致使产率较低。又研究了将Michael加成产物单水解然后脱羧的方法,该方法不仅降低了反应温度,而且使用更易处理的DMF为反应溶剂,经两步反应以85%的产率得到二氢茉莉酮酸甲酯。     

关环反应合成鸢尾酮

研究了以9,10-环亚甲基假紫罗兰酮为原料,经关环反应合成鸢尾酮的工艺,并对该关环反应机理进行了初步探讨。实验结果表明,适宜的工艺条件为:反应温度-70℃,物料摩尔比n(9,10-环亚甲基假紫罗兰酮)∶n(氯磺酸)为1∶4,反应45 min,鸢尾酮的收率为90.1%。产品中α-鸢尾酮、β-鸢尾酮和γ-鸢尾酮的含量分别为60.2%、29.0%和8.0%(GC,峰面积归一化法);采用NMR确证了α-鸢尾酮的结构。关环反应机理的初步探讨表明关环反应应在低温下快速完成。     

新型含紫罗兰酮基查尔酮的合成与表征

在碳酸钠和氢氧化钠催化下,β-紫罗兰酮和5,6-环氧-β-紫罗兰酮与芳香醛于室温下研磨1～15 min,制备了8种新型含紫罗兰酮基查尔酮,其结构经1H NMR、MS、IR和元素分析表征。 结果表明,β-紫罗兰酮、苯甲醛、Na2CO3与NaOH的物质的量比为20∶20∶5∶15时,收率可达87.1%～94.8%,苯甲醛环上吸电子基团可促进反应进行。     

4,4’-二氯二苯酮合成二氮杂萘联苯酮结构聚醚砜酮的研究

以4-(4-羟基苯基)*2,3-二氮杂萘-1-酮(DHPZ)、4,4’-二氯二苯砜(DCS)和4,4’-二氯二苯酮(DCK)为原料,采用分步加料的方法,合成了系列高分子量的聚芳醚砜酮共聚物(PPESKs),其特性黏度在0.40 ～0.61dL/g之间,解决了由于DCK活性低不适合用于聚芳醚合成的问题.采用FTIR、示差...     

溴代卓酚酮基础的双查尔酮的合成（英文）

卓酚酮基础的双查尔酮3,3′-{(1E,1′E)-1,4-苯撑双[(1E)-3-羰基并-1-烯-1,3-二基]}双卓酚酮(1)与2.1倍或4.2倍物质的量的液溴在乙酸溶剂中直接进行溴化反应.该溴化反应选择性的发生在卓酚酮环上,得到相应的7-溴卓酚酮(2)和5,7-二溴卓酚酮基础的双查尔酮(3),收率分别为81%和73%,其结构通过波谱数据和元素分析得以证实.     

含二氮杂萘酮结构聚芳醚腈酮酮的合成及表征

以5种含杂萘联苯结构的单体与2,6-二氯苯腈、1,4-二(4-氟代苯甲酰基)苯为原料进行亲核缩聚反应,制备了一系列含有杂萘联苯结构的新型聚芳醚腈酮酮树脂.其特性粘度在0.51~1.15 dL.g-1之间.采用FT-IR,示差扫描量热仪(DSC),热重分析仪(TGA)对聚合物的结构和性能进行了表征,结果表明,聚芳醚腈酮酮的玻璃化转变温度(Tg)在252~294℃之间,10%热失重温度(Td)在457℃以上,具有优异的耐热性能.聚芳醚腈酮酮均可溶解于N-甲基吡咯烷酮(NMP)、N,N-二甲基乙酰胺(DMAc)、和氯仿等极性非质子型有机溶剂中,聚合物均可溶解于NMP后浇铸得到透明的、韧性好的薄膜.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.