1-甲基-2-苯基-5-溴1H-苯并咪唑的合成研究

1-甲基-2-苯基-5-溴-1H-苯并咪唑是制备抗癌药物和有机电场致发光器件的中间体。以N-甲基-2-硝基苯胺为原料,经过苯环的溴代、N-苯甲酰化反应得到N-(2-硝基-4-溴苯基)-N-甲基苯甲酰胺;再经硝基还原和分子内脱水闭环反应合成了1-甲基-2-苯基-5-溴-1H-苯并咪唑。化合物结构用1H-NMR、13C-NMR、IR表征,纯度用HPLC确定。     

1-(5-萘酚-7-磺酸)-3-[4-(苯基偶氮)苯基]-三氮烯的合成及与阳离子表面活性剂的显色反应

报道了1-（5-萘酚-7-磺酸）-3-[4-（苯基偶氮）苯基]-三氮烯（NASAPAPT）的合成，研究了该试剂与阳离子表面活性剂溴化十二烷基二甲基苄铵（DDMBAB），溴化十六烷基三甲铵（CTMAB）、溴化十六烷基吡啶（CPB）、溴化十四烷基吡啶（TPB）显色反应的条件。测定了显色反应的灵敏度，符合比尔定律的范围。建立了光度法测定微量阳离子表面活性剂的新方法。     

2-甲基-1,8-萘啶衍生物的甲基溴代反应

报道了2-甲基-1,8-萘啶衍生物的甲基溴化反应,以N-溴代琥珀酰亚胺(NBS)为溴化剂、红外光为引发剂,得到单溴代产物2-溴甲基-1,8-萘啶衍生物及其二溴代副产物2-二溴甲基-1,8-萘啶衍生物,对比了两种不同的反应条件,通过对影响甲基溴化产物产率的反应条件进行优化改进,得到单溴代产物的较优合成条件为：NBS的用量为原料的1.2倍,500 W红外灯为光源,反应时间为2 h。 该反应条件下,单溴代产物的产率可达到54.6%。     

2-(1-溴-2-萘氧甲基)-5-芳基-1,3,4-噁二唑的合成与表征

以碳酸钠作缚酸剂,1-溴-2-萘氧甲酰肼与芳酰氯反应制得N,N′-二酰基肼,后者在POCI3作用下脱水环化成2-(1-溴-2-萘氧甲基)5-芳基-1,3,4-噁二唑。其结构经^1H NMR,IR,MS和表征元素分析,并对其裂解途径进行了探讨。     

(2S)-(+)-2-溴-1-(6'-甲氧基-2'-萘基)丙-1-酮的不对称合成

以(2R,3R)-酒石酸二甲酯为手性辅助剂,6-甲氧基-2-丙酰基萘经缩酮化、溴化铜不对称溴化、水解等反应合成了(2S)-2-溴-1-(6'-甲氧基-2'-萘基)丙-1-酮。总收率94%。     

卤化吡啶具有区域选择性的锂化反应与2,6-二甲氧基-3-溴-4-二苯基膦基吡啶的合成

在卤化吡啶的锂化反应的区域选择性研究基础上,以2,6-二甲氧基吡啶为原料,经溴化反应、邻位锂化反应和亲电取代反应制备了2,6-二甲氧基-3-溴-4-二苯基膦基吡啶,最终收率可达57．9％。     

2-甲基-3-芳基烯丙基三苯基溴代鏻的合成

取代苯甲醛经醇醛缩合、硼氢化还原、溴代反应和成盐反应合成了２-甲基-３-间硝基苯基烯丙基三苯基溴化特和２-甲基-３-对硝基苯基烯丙基三苯基溴化鏻两个化合物,收率分别达８６．４％和６９．０％。结构经ＩＲ,1ＨＮＭＰ确证。     

微波辐射下以1,3-二溴-5,5-二甲基乙内酰脲为溴代试剂合成3-溴黄酮

报道了在微波辐射下以1,3-二溴-5,5-二甲基乙内酰脲(DBDMH)为溴化试剂合成3-溴黄酮的新方法,系统考察了反应温度、时间及反应物配比对反应收率的影响.     

2-溴甲基取代的[1,3]二氧戊环并[4,5-g]喹啉-7-甲酸乙酯的合成(英文)

6-甲基-[1,3]二氧戊环并[4,5-g]喹啉-7-甲酸乙酯(1)与N-溴代丁二酰亚胺(NBS)在150W白炽灯照射的条件下有效的发生自由基溴化反应,以较好的收率(75%)得到想要的单溴化产品6-(溴甲基)-[1,3]二氧戊环并[4,5-g]喹啉-7-甲酸乙酯(2)。本文所开发的自由基溴化方法与文献相比,单溴化产品的收率提高了46%。另外,该溴化反应中所生成的少量副产品也进行了分离提纯,其结构经波谱分析证实为9-溴-6-甲基-[1,3]二氧戊环并[4,5-g]喹啉-7-甲酸乙酯(3)。     

2-溴-4,5-二甲氧基苯甲醛高选择性脱甲基反应

以藜芦醛为起始原料,经溴化反应制得中间体2-溴-4,5-二甲氧基苯甲醛,选择性脱除甲基合成了6-溴香草醛和6-溴异香草醛,收率分别为87.0%和80.2%,其结构经¹H NMR确证。     

Meyers’ bicyclic lactam formation under mild and highly stereoselective conditions

New and mild conditions to prepare chiral bicyclic lactams in high yields and high diastereoselectivities are reported herein. This approach based on the activation of the carboxylic acid by means of Mukaiyama’s reagent is an excellent alternative to Meyers’ dehydrating conditions and provide the main advantage to work at lower temperature (40 °C). Higher diastereoselectivity was obtained with 5,7-bicyclic lactams (de = 82% instead of 44% under standard dehydrating conditions).     

布洛芬-扑热息痛孪药的合成

以布洛芬（IPF）和扑热息痛（PCM）为原料,无水丙酮和乙酸乙酯为溶剂,二环己基碳二亚胺（DCC）为脱水剂,4-二甲氨基吡啶（DMAP）为催化剂,合成了布洛芬-扑热息痛孪药（PHI）,以重结晶法对目标产物进行纯化,产物结构经IR和1H NMR确定。 探讨了原料比例、脱水剂用量、催化剂用量、反应时间和溶媒用量对目标物产率的影响,并采用正交试验筛选最优合成工艺,最终确定的最优反应条件为:n(PCM)∶n(IPF)=1∶1.5,催化剂的最佳用量为布洛芬质量的10%,反应时间为8 h,溶媒体积为70 mL（V(乙酸乙酯)∶V(丙酮)=1∶1）,在该条件下,目标物PHI的产率为66.53%。     

Convenient Synthesis of Bis（oxazoline） Dicarboxylate Derivatives

The synthesis of bis(oxazoline) dicarboxylate derivatives was investigated.Diethyl-aminosulfur trifluoride (DAST) was used as a convenient cyclization reagent in the synthesis of bis(oxazoline) dicarboxylate derivatives,which can not be obtained by the general method using MsC1 and Et3N as dehydrating cyclization reagent.     

Effective synthesis of dialkyl carbonate from CO2 and alcohols using dibutyltin(IV) oxide catalyst and dehydrating agents

The combination of a dibutyltin(IV) oxide catalyst with an ortho ester as the dehydrating agent exhibited high activity for the direct synthesis of diethyl carbonate from CO₂ and ethanol in 78% yield. With water as a by-product limiting the reaction, a recoverable dehydrating agent is required. When alkoxysilanes were employed for this purpose, various dialkyl carbonates were obtained in yields of 33–45%.     

A practical synthesis of N-tosylimines of arylaldehydes

Synthesis of N-tosylimines of arylaldehydes was carried out by the reaction of arylaldehydes and p-toluenesulfonamide in methylene chloride in the presence of trifluoroacetic anhydride as a dehydrating agent.     

Polymer-supported triphenylphosphine ditriflate: a novel dehydrating reagent

A new type of polymeric dehydrating reagent, readily prepared by the treatment of polymer-supported triphenylphosphine oxide with triflic anhydride, was found to be effective in a variety of dehydration reactions such as ester and amide formation; the polymer-supported triphenylphosphine oxide was easily recovered and reused several times without the loss of activity.     

Guanine Substitutions Prevent Conformational Switch from Antiparallel to Parallel G-Quadruplex

Guanine quadruplexes, recently reported to form in vivo, represent a broad spectrum of non-canonical conformations of nucleic acids. The actual conformation might differ between water solutions and crowding or dehydrating solutions that better reflect the conditions in the cell. Here we show, using spectroscopic techniques, that most guanine substitutions prevent the conformational switch from antiparallel or hybrid forms to parallel ones when induced by dehydrating agents. The inhibitory effect does not depend on the position of the substitution, but, interestingly, on the type of substitution and, to some extent, on its destabilising potential. A parallel form might be induced in some cases by ligands such as N-methyl mesoporphyrin IX and even this ligand-induced switch is inhibited by guanine substitution. The ability or inability to have a conformation switch, based on actual conditions, might significantly influence potential conformation-dependent quadruplex interactions.     

2,4-二硝基酚与二氟溴甲基膦酸二乙酯反应的研究

酚在碱性条件下与卤代烃反应生成相应的芳香醚,是典型的亲核取代反应,对于2,4-二硝基酚和二氟溴甲基膦酸二乙酯在碱性条件下的反应,其实验过程包括室温中和,甲苯回流脱水和亲核取代等三步反应。对产物进行了提纯和一系列的表征,结果发现主要生成了一种酚醚化合物。     

Facile characterization of polymer-supported reagents using cross polarization magic angle spinning method in solid state 13C-NMR

Polymer-supported (PS) reagents can be easily characterized using a cross polarization magic angle spinning method in solid state (13)C-NMR. The technique was applied to the characterization of PS-dimethylimidazolidinone, analogue to potential heterogeneous dehydrating agent.     

Synthesis of dimethyl carbonate from methanol and supercritical carbon dioxide

The synthesis of dimethyl carbonate (DMC) from methanol and supercritical carbon dioxide over various base catalysts has been studied. Compounds of group-I elements (Li, Na and K) were used as base catalysts. The promoter and the dehydrating agent were also used to enhance the yield of DMC. The effects of the catalysts, promoter and dehydrating agent on the yield of DMC were investigated. By-products such as dimethyl ether (DME) and C₁–C₂ hydrocarbons were formed with the DMC as a main product. The yield of DMC with different alkali metal catalysts ranked in the following order: K > Na > Li. The catalysts of the metal-CO₃ compounds were more effective than the metal-OH compounds in DMC synthesis. The maximum DMC yield reached up to about 12 mol% in the presence of K₂CO₃ (catalyst), CH₃I (promoter) and 2,2-dimethoxypropane (dehydrating agent) at 130–140°C and 200 bar. The reaction mechanism of DMC synthesis from methanol and supercritical carbon dioxide was proposed.