苯并呋喃-3-甲酸乙酯的合成方法改进

苯并呋喃骨架广泛存在于天然产物与合成药物中,许多苯并呋喃类衍生物具有重要的生理、药理和毒理学活性,其合成方法备受人们的关注。本文通过"一锅法"合成苯并呋喃-3-甲酸乙酯,在Et_3N存在下以甲苯作溶剂、邻碘苯酚与丙炔酸乙酯的投料摩尔比1∶1. 5,室温反应20min后加入K_2CO_3和Pd(OAc)2/PPh3,85℃反应3. 5h,产率达到78%。本方法避免了反应过程中使用毒性较大的重氮类化合物,反应步骤少,时间短,操作简便,产率较高,并且可以较方便地对目标分子进行结构改变和修饰,对类似化合物的合成具有指导作用。     

2-取代芳基苯并呋喃类化合物的合成

以香草醛和丙二酸为原料,经Knoevenagel缩合、酯化、仿生氧化偶联、DDQ脱氢、还原和氧化等反应合成了3种新的2-取代芳基苯并呋喃类化合物,其结构经1H NMR,IR和MS表征。两分子阿魏酸甲酯仿生氧化偶联为它的二聚体是合成的关键步骤。     

4-哌啶甲酸乙酯的合成

以异烟酸为起始原料,经酯化和氢化还原反应制得药物中间体4-哌啶甲酸乙酯。酯化、氢化和总收率分别为84.6%,87%,75.4%。催化剂Pd/C可重复使用10次。     

(2R,4S)-4-甲基-2-哌啶甲酸乙酯的合成

以S-(-)-α-苯乙胺为原料,经一锅法制得1-(1-苄基)-6-乙氧羰基-4-甲基-3,4-二氢哌啶(3),收率58.7%。以10%Pd/C为催化剂,3经催化氢化脱苄合成了4-甲基-2-哌啶甲酸乙酯(4),收率96%;4通过减压分馏得(2R,4S)-4,含量95%,其结构经1H NMR,IR和MS确证。     

2-(2,6-二烷氧基苯基)苯并呋喃衍生物的合成

以焦性没食子酸、4-羟基苯甲醛和酚为原料, 以邻碘代苯酚与苯乙炔衍生物的Sonogashira偶联及其连串化反应生成苯并呋喃环为关键步骤, 设计合成了一系列2-(2 ,6 -二烷氧基苯基)苯并呋喃衍生物, 并对产物进行了¹H NMR, ¹³C NMR, MS等表征.     

2-(取代哌嗪-1-甲基)-3-喹啉甲酸乙酯及其衍生物的合成、 表征及晶体结构

以邻硝基苯甲醛为起始原料, 经还原、Friedländer 缩合反应合成2-甲基-3-喹啉甲酸乙酯(2), 2经N-溴代丁二酰亚胺(NBS)溴代得到化合物3, 3再与N-取代哌嗪5a～5p 发生SN2亲核取代反应, 合成一系列2-(取代哌嗪-1-甲基)-3-喹啉甲酸乙酯及其衍生物6a～6p. 它们的结构通过元素分析, IR, 1H NMR, 13C NMR和MS进行了鉴定和表征, 并用X射线衍射法测定了化合物6n的晶体结构.     

水介质中N-芳基-N'-(2-苯并呋喃甲酰基)硫脲及1-芳甲酰基-4-(2'-苯并呋喃甲酰基)氨基硫脲的合成

苄基三乙基氯化铵(TEBA)存在的水介质中, 2-苯并呋喃甲酰氯、硫氰酸铵与芳胺或芳甲酰肼在室温条件下经一步反应合成N-芳基-N'-(2-苯并呋喃甲酰基)硫脲或1-芳甲酰基-4-(2'-苯并呋喃甲酰基)氨基硫脲, 其中前者尚未见文献报道. 与其它合成方法相比, 该法操作简单、反应条件温和、环境友好.     

N-甲基-2-(4-取代哌嗪)-N-[3-(萘氧基)-3-(2-噻吩基)丙基]乙酰胺衍生物的设计与合成

以N-甲基-3-(1-萘氧基)-3-(2-噻吩基)-丙胺(度洛西汀)为原料,通过N-酰氯化反应和N-烷基化反应,合成了5个新型的N-甲基-2-(4-取代哌嗪)-N-[3-(萘氧基)-3-(2-噻吩基)丙基]酰胺衍生物,其结构经1H NMR,IR和MS表征。     

新型2-苯甲酰基苯并呋喃类似物的合成

以水杨醛与2-溴-4’-氟苯乙酮为原料,经取代和分子内缩合反应合成了中间体2-苯甲酰基苯并呋喃(1);在碱性条件下,1分别与咪唑,N-甲基哌嗪和二乙胺等反应,合成了6个新型的2-苯甲酰基苯并呋喃含氮类似物,收率63%~82%,其结构经1H NMR,13C NMR,IR和HR-MS表征。     

4-叔丁氧羰酰胺基-呋喃-2-甲酸甲酯的合成

以呋喃甲醛为起始原料,经过5步反应合成了天然产物Proximicin A的     

Practical Synthesis of 1-(7-Fluoro-naphthalen-1-yl)piperazine Hydrochloride

A practical and scalable preparation of 1-(7-fluoronaphthalen-1-yl)-piperazine hydrochloride (1) is reported. The original route for the synthesis of this compound involved the use of 1-amino-7-fluoronaphthalene and bis(2-chloroethyl)amine hydrochloride, two highly toxic compounds. A new protocol has been developed that employs a palladium-catalyzed Buchwald–Hartwig cross-coupling reaction between 1-Boc-piperazine and 1-bromo-7-fluoronaphthalene followed by piperazine deprotection with HCl gas. In addition, an efficient palladium removal protocol allowed for the preparation of the target molecule with less than 20 ppm of this metal. This methodology has been successfully implemented to produce multigram quantities of 1 with excellent purity and low palladium content.     

2-(4-溴甲基苯基)丙酸乙酯的合成

以甲苯为原料,对甲苯磺酰乳酸乙酯为Friedel—Crafts烷基化试剂,N-溴代丁二酰亚胺为溴化剂,合成了洛索洛芬的关键中间体——2-（4-溴甲基苯基）丙酸乙酯。其结构经1^H NMR,IR和MS表征。优化反应条件为：催化剂50．0g,回流反应6h,甲苯104．0mL,侧链溴化的引发剂为过氧化苯甲酰。总收率70％。     

Synthesis and Crystal Structure of Ethyl 1-（2-bromoethyl）-3-（4-meth-oxyphenyl）-1H-pyrazole-5-carboxylate

The title compound ethyl 1-(2-bromoethyl)-3-(4-methoxyphenyl)-1H-pyrazole-5-carboxylate 1 has been synthesized and structurally characterized by single-crystal X-ray diffraction.The crystal is of monoclinic(C15H17BrN2O3,Mr = 353.22),space group C21 with a = 24.691(7),b = 6.7678(17),c = 17.884(5) ,β = 97.184(5)o,V = 2965.1(13) 3,Z = 8,Dc = 1.583 g.cm-3,F(000) = 1440,μ = 2.784 mm-1,the final R = 0.0260 and wR = 0.0596 for 2684 observed reflections with I > 2σ(I).All the carbon atoms in the molecule are nearly coplanar except C(15),with a large conjugated system among the carbonyl group,pyrazole ring and the benzene ring.Three non-classical intermolecular hydrogen bonds help to stabilize the crystal lattice.The regioselectivity was rationalized based on the coordination of potassium ion with the N-anion and the carbonyl oxygen atom.     

2-(4-羟基苯基)-3,3,3-三氟丙酸乙酯的合成研究

报道了以苯酚和三氟丙酮酸乙酯为起始原料,在温和条件下合成高产率的2-(4-羟基苯基)-3,3,3-三氟丙酸乙酯的一条新途径.该途径包括无水碳酸钾催化的苯酚与三氟丙酮酸乙酯间的亲电取代反应、由此形成的产物的选择性侧连羟基的氯代反应和随后的硼氢化钠还原反应.     

Reaction of Ketene Dithioacetals with Pyrazolylcarbohydrazide:Synthesis and Biological Activities of Ethyl 5-Amino-1-(5''''- methyl-1''''-t-butyl-4''''-pyrazolyl)carbonyl-3-methylthio-1H-pyrazole-4-carboxylate

Introduction Pyrazole and its derivatives represent one of the most active classes of compounds possessing a wide spectrum of biological activities. During the past years, considerable evidence has been accumulated to demon-strate the efficacy of pyrazole derivatives including an-tibacterial,1 antifungal,2 herbicidal,3 insecticidal4 and other biological activities.5-7 Up to now, a great variety of these kind of compounds have been synthesized, among which some commercially pesticides have been…     

(S)-2-乙氧基-3-(4-羟基苯基)丙酸乙酯的合成

(S)-2-乙氧基-3-(4-羟基苯基)丙酸乙酯的合成;二乙氧基乙酸乙酯;Horner Wadswordth Emmons反应;催化氢化;化学拆分;（S） 乙氧基（羟基苯基）     

Synthesis and Crystal Structure of Ethyl 3-（4-Chlorophenyl）-3,4-dihydro-6-methyl-4-oxo-2- （pyrrolidin-1-yl）furo[2,3-d]pyrimidine-5-carboxylate

The crystal structure of the title compound ethyl 3-（4-chlorophenyl）-3,4-dihydro-6- methyl-4-oxo-2-（pyrrolidin-1-yl）furo[2,3-d]pyrimidine-5-carboxylate （C20H20ClN3O4, Mr= 401.84） has been prepared and determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/n with a = 20.6215（9）, b = 8.5311（4）, c = 21.6886（9） A^°, β = 91.607（1）°, V = 3814.0（3）A^°^3, Z = 8, Dc = 1.400 g/cm^3, F（000） = 1680, μ = 0.233 mm^-1, R = 0.0718 and wR = 0.1545 for 6717 observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals two crystallographically independent molecules in the asymmetric unit.     

Synthesis and Crystal Structure of Ethyl2—（2—Amino—3—ethoxycarbonyl—4H—benzopyran—4—yl）cyanoacetate

1 INTRODUCTION Inorganic solid supports as catalysts resulting in higher selectivity, milder conditions and easier work-up have been reported as useful catalysts for many reactions [1~3]. Recently, we have reported the Knoevenagel condensation catalyzed by KF-Al2O3[4]. In this paper, we discussed the crystal structure of the title compound synthesized by the reaction of salicylaldehyde and ethyl cyanoacetate in DMF using the catalyst KF-Al2O3 at room temperature KF-Al2O3. In or…     

2-(4-甲基苯基)-4-(4-甲氧基苯基)噻唑-5-甲酸乙酯的合成

以对甲氧基苯甲酸为原料,经5步反应合成了新化合物2-(4-甲基苯基)-4-(4-甲氧基苯基)噻唑-5-甲酸乙酯,其结构经1H NMR,MS及X-射线单晶衍射确证。