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1.
胡家栋  文雯  陈乐  方晓武 《化学通报》2021,84(3):279-283
本文开发了一种天然产物2-羟基-3,4,6-三甲氧基查尔酮(1)的十克级规模快速合成方法。通过改良合成2-羟基-3,4,6-三甲氧基苯甲醛(7)的甲基化和甲酰化条件,将7的合成总收率从文献报道的22%提高至68%。并以7为原料在乙腈为溶剂、80℃加热的条件下通过Wittig反应在50mmol规模以85%的收率合成了产物1。  相似文献   

2.
以溴化铜或氯化铜为卤化剂 ,6-甲氧基 -2 -丙酰基萘经羰基 α-卤化、1 ,2 -丙二醇缩酮化、醋酸锌或氧化锌催化重排和水解等反应合成外消旋体萘普生 ,总收率为 85 %~ 90 .4% (以 6-甲氧基 -2 -丙酰基萘计 ) .“一锅法”重排合成外消旋体萘普生 ,不需分离中间体 ,操作简便、收率高 .以氯化铜为卤化剂、氧化锌为催化剂的重排合成工艺较佳  相似文献   

3.
以2-氨基/乙酰氨基-7-羟基-1,8-萘啶为原料和POBr3反应,简单高效合成得到六个7-溴代1,8-萘啶衍生物L1-L6。反应在较高温度或延长反应时间下易产生自由基取代反应,通过对影响2-溴代1,8-萘啶产物产率的反应条件(反应温度、反应时间、有无自由基猝灭剂)进行优化,得到各7-溴代1,8-萘啶衍生物的最佳合成条件。化合物L1、L2、L3、L5的最佳合成条件为60℃(10min),若高温或延长时间反应,可加FeCl_3抑制自由基以保证产率;化合物L4、L6的最佳条件为100℃(30min)。优化的条件下,各7-溴代1,8-萘啶衍生物产率分别为57.2%、61.5%、56.8%、46.8%、62.7%和53.8%。  相似文献   

4.
以苯胺为原料,通过传统方法合成靛红,靛红与盐酸羟胺反应生成3-羟基亚氨基-2-吲哚酮,再通过钯碳加氢还原生成3-氨基-2-吲哚酮。合成中,采用钯碳加氢的还原方式,产物收率提高(收率82.76%,较文献提高了11.8%),后处理更简单。该方法可操作性高、成本低、产生三废少,是一条适合大规模生产3-氨基-2-吲哚酮的新合成工艺路线。  相似文献   

5.
先以间二氯苯、氯乙酰氯和咪唑为原料合成β-( 1 -咪唑基 ) -2 ,4 -二氯 -α-苯乙醇 ( ) ,再以二卤苯为原料合成α-氯 -卤代乙苯 ( a~ d) ,然后 , 分别与 a~ d反应 ,生成α-(α -甲基 -卤代苄氧基 ) -β-( 1 -咪唑基 ) -2 ,4 -二氯乙苯硝酸盐 4个新化合物 ,产率分别为 66.8% ,78.5% ,76.8%和 81 .2 % ,新化合物的结构经元素分析 ,IR和 1H NMR表征  相似文献   

6.
邻苯二甲酸酐与丙二酸反应合成邻乙酰基苯甲酸(1);1经酰氯化反应得邻乙酰基苯甲酰氯(2);2与伯胺反应合成了3个1-羟基-1-甲基-3-氧-异吲哚化合物,总收率65.0%~76.8%,其结构经1H NMR, 13C NMR, IR和MS表征.  相似文献   

7.
以5-羟基-2-羟甲基-4-吡喃酮为原料,经羟基保护、迈克尔加成、亲核取代、Mitsunobu反应、肼解及缩合等反应合成了BAL30072关键中间体——(Z)-2-(2-三苯甲基氨基噻唑-4-基)-2-(1,5-二(二苯甲氧基)-4-吡啶酮-2-基甲氧基亚胺)乙酸,总收率23%,其结构经1H NMR和MS确证。该合成工艺已放大到公斤级规模。  相似文献   

8.
徐玲  程博闻  任元林 《应用化学》2011,28(5):605-607
以新戊二醇、三氯氧磷、烯丙醇和金属钠为原料,经过2步反应合成了新型反应型阻燃化合物5,5-二甲基-2-磷杂-1,3-二噁烷-2-基烯丙基磷酸酯。 采用元素分析、FTIR、MS和1H NMR等测试技术对其结构进行了表征。 对合成工艺进行了探讨,当n(Na)∶n(烯丙醇)=1∶2,于冰水浴反应2 h,再于30 ℃反应6 h时,产率可达55.5%。 TG分析显示,该化合物的起始分解温度为130.2 ℃,800 ℃时仍有23%的残炭率,说明该化合物具有较好的热稳定性和成炭性。  相似文献   

9.
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%。  相似文献   

10.
以间氯苯酚为原料,经乙酰化、Fries重排、O-甲基化和氧化反应合成了2-甲氧基-4-氯苯甲酸,总收率54.1%,纯度98.2%.  相似文献   

11.
We have developed a highly efficient reaction for catalytic asymmetric addition of malonates to dihydroisoquinolines using chiral Pd(II) complexes. In the reactions, substrates with various substitution patterns were available, and the reactions were complete within several hours (<3 h in most cases) under mild reaction conditions, affording various optically active C1-substituted tetrahydroisoquinoline derivatives (up to 98% yield, up to 97% ee). Furthermore, slow addition of DDQ allowed the in situ generation of the reactive intermediate from the corresponding N-Boc-protected amine, and dehydrogenative addition reaction was successfully demonstrated.  相似文献   

12.
The reaction of poly(styryl)lithium (PSLi) with styrene oxide (SO) in benzene solution has been investigated. In addition to the functionalized polymer (83.5 wt %) the product mixture consisted of unfunctionalized polymer (9 wt %) and a dimeric product (5.6 wt %). The structure of the dimeric product was determined to be the head-to-head dimer. The regiochemistry of the addition reaction was unselective: 53 mol % addition to the methylene carbon and 47 mol % corresponding to addition to the hindered, methine carbon. Based on the formation of the dimer and the lack of regioselectivity, a pathway involving electron transfer from PSLi to SO was proposed. To further investigate the propensity to react via this electron-transfer mechanism, the SO functionalization of the adduct of PSLi with 1,1-diphenylethylene was investigated as well as the functionalization of PSLi with 1,1-diphenylethylene oxide.  相似文献   

13.
The addition of alkynyl dimethyl aluminum compounds onto N-p-tolylsulfinylimines was investigated. The reaction was proved to be totally regioselective, leading to propargylamines with high diastereoselectivity (up to 99% de). Addition of aluminum derivatives gave a reversal of diastereoselectivity compared to the addition reaction of lithium acetylide.  相似文献   

14.

In this work, a new methacrylate phosphonate monomer synthesis was described according to a two-step reaction. First the monoaddition of thioglycolic acid onto dimethylvinyl phosphonate monomer led to dimethyl–5-carboxymethyl-2-thiaethylphosphonate, a new phosphonate acid compound. This reaction also led to the thioester homologue of dimethyl–5-carboxymethyl-2-thiaethylphosphonate with a 15% yield by reaction of a thioglycolic acid thioester with dimethylvinyl phosphonate. Second, dimethyl carboxy-4-thia-butyl phosphonate reacted with glycidyl methacrylate. This epoxy-acid addition reaction was catalyzed by chromium salt at 70°C and led to the new methacrylate phosphonate monomer. We showed that only the secondary alcohol was obtained via a β addition. The two-step reaction final yield was calculated to be about 85%.  相似文献   

15.
Highly enantioselective Michael addition of malonates to enones was achieved using a mixed catalyst consisting of a primary β-amino acid, O-TBDPS (S)-β-homoserine, and its lithium salt. Various cyclic and acyclic enones were converted into 1,5-ketoesters in high yields (up to 92%) with high enantioselectivity (up to 97% ee) under mild reaction conditions. Details of synthesis of the catalyst, optimization of the reaction conditions for the Michael addition reaction, and a plausible reaction mechanism are described.  相似文献   

16.
以胡椒醛和丙二酸酯为原料,经Knoevenagel缩合、常压催化氢化、缩合、加成、酰化5步反应合成了法西多曲,其结构经元素分析、IR和1H NMR表征。总收率72.1%。  相似文献   

17.
Fanny Valleix 《Tetrahedron》2005,61(31):7420-7424
The copper-amidophosphane-catalyzed asymmetric addition reaction of dialkylzinc reagents with β-aryl and β-alkylnitroalkenes afforded the corresponding nitroalkanes with moderate to good enantioselectivities (54-80% ee). The performance was highly dependent on the reaction procedure where the addition of nitroalkene to the mixture of copper-amidophosphane and dialkylzinc gave higher ee than the addition of dialkylzinc to a mixture of copper-amidophosphane and nitroalkene.  相似文献   

18.
The tandem synthesis of naphthoquinones was conducted from the reaction of laccase-generated quinones and acyclic dienes via Diels-Alder reaction. This reaction was carried out under mild condition in aqueous medium and yielded naphthoquinones up to 80%. In addition, the effect of solvent was also investigated and water was shown to be optimal for this reaction.  相似文献   

19.
The 1,3-dipolar cycloaddition reactions of stable nitrile oxides with indole o-quinodimethanes have been examined. In all cases the ‘exo-anti’ addition products, dispiroisoxazolines, were isolated in moderate to good yields (25-47%). In addition, from the reaction of one of the indole quinodimethanes with mesitonitrile oxide the ‘exo-syn’ addition product was isolated in 7% yield along with the remarkable indole quinodimethane dimerization and cycloaddition product, which was isolated in 13% yield. An analogous dimerization and cycloaddition product was isolated in 18% yield from the reaction of the N-acetyl-indole quinodimethane with mesitonitrile oxide. In the case of the reaction of the N-benzoylindole quinodimethane with the 2,6-dichlorobenzonitrile oxide an oxime was also isolated in 13% yield. The proposed reaction mechanism is supported by semiempirical (AM1) MO calculations via FMO interactions. The observed selectivity was explained by an investigation of the transition states carried out also for analogous dispiroisoxazolines.  相似文献   

20.
A facile triphenylphosphine-catalyzed Michael addition of alcohols to acrylic compounds was described. The reaction was carried out in open air at refluxing temperature in the presence of 10 mol% PPh3. Michael addition of saturated and unsaturated alcohols to acrylonitrile or acrylates has been examined. The reaction gave β-alkoxy derivatives with isolated yields of 5%-79%. PPh3 is cheaper and more stable than those trialkylphosphines previously used for the similar reactions, and the products can be easily separated from the reaction mixture via distillation.  相似文献   

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