共查询到20条相似文献,搜索用时 11 毫秒
1.
A novel and straightforward solid-phase synthesis of malondiamides containing a free nitrogen has been developed. These intermediates, which can be directly obtained in good yield and purity, can be further derivatised. This approach can be used for the synthesis of large split-and-mix-libraries. 相似文献
2.
Serge Djekou Armand Gellis Patrice Vanelle Hussein El‐Kashef 《Journal of heterocyclic chemistry》2006,43(5):1225-1229
3.
Cheng Jiang Qi Dong You Department of Medicinal Chemistry China Pharmaceutical University Nanjing China 《中国化学快报》2007,18(6):647-650
An efficient synthesis of 3,4-dihydropyrimidin-2(1H)-one derivatives using formic acid as catalyst, from aldehydes,β-ketoester and urea(thiourea) without solvent under the irradiation of microwave is described. Compared with the classical Biginelli reaction, this new method has the advantage of good yields (77-94% for aromatic aldehydes) and short reaction time (3-8 min). 相似文献
4.
An efficient synthesis of 1,4-dihydropyridines using lanthanum oxide as a catalyst from aldehydes,β-ketoester and ammonium acetate without solvent under the irradiation of microwave is described.Compared with the classical Hantzsch reaction,this new method has the advantage of good yield(90-98%) and short reaction time(40-80 s). 相似文献
5.
Ling-Kuen Huang 《Tetrahedron》2007,63(24):5323-5327
A rapid nucleophilic displacement reaction of 6-chloropurine, 2-amino-6-chloropurine and 5-bromocytosine with various nucleophiles under focused microwave irradiation is described. Using this method, the desired products were obtained with the yields up to 99% in a short reaction time. 相似文献
6.
《Tetrahedron: Asymmetry》2014,25(13-14):1008-1014
The scope and limitations of microwave-assisted glycosylation for the preparation of various alkyl l-rhamnoside amphiphiles were investigated. Straightforward coupling of hydrophilic unprotected sugar and hydrophobic high molecular weight alcohols, in the presence of p-toluenesulfonic acid as a promoter, yielded structurally different compounds in very good yields (37–87%). A homologous series including 17 examples of alkyl α-l-rhamnoside amphiphiles varying in chain structure (C4–C20) is reported. The structures of the new derivatives were determined by NMR spectroscopy and quantum chemical calculations. Molecular geometry optimizations of different ring forms (1C4 and 4C1) and anomeric configurations were carried out using DFT calculations. Herein we demonstrate the advantages of microwave irradiation for the preparation of a broad variety of linear and branched-chain alkyl α-l-rhamnosides. The application of this approach to the synthesis of new natural non-ionic surfactants makes this method attractive because of their potential use in biomedical and pharmaceutical chemistry. 相似文献
7.
《Tetrahedron letters》1997,38(39):6875-6876
1-Arylpiperazines, finding wide applicability in pharmaceuticals were synthesized easily under microwave irradiation from bis(2-chloroethyl)amine hydrochloride and substituted anilines without any solvent. The reaction time was just 1–3 mins. 1-Arylpiperazines were synthesized in 53 to 73% yields. Potent serotonin ligands like Trifluoromethylphenylpiperazine (TFMPP) and 3-Chlorophenylpiperazine (mCPP) were also prepared in just 1 min. and 2 mins. respectively. 相似文献
8.
[reaction: see text]. Alpha-carbolines are interesting core structures for designing DNA-interacting small molecules. However, these compounds are not commercially available and their synthetic methods are low yielding or time consuming. The shortest synthetic route, the modified Graebe-Ullmann reaction, has been optimized by using microwave heating in four different types of apparatus to give shorter reaction times and enhanced yields. Optimized conditions enabled the preparation of a small library of alpha-carbolines. 相似文献
9.
Hong-Jun Wang William G. Earley Robert M. Lewis Rajiv R. Srivastava Andrew J. Zych David M. Jenkins David J. Fairfax 《Tetrahedron letters》2007,48(17):3043-3046
A highly efficient one-pot, two-step microwave procedure has been developed for the synthesis of 4-substituted 1-heteroarylpiperazines. Microwave heating of heteroaryl chlorides with 1,4-diazabicyclo[2.2.2]octane (DABCO) at 160 °C for 15 min yielded 1-heteroaryl-4-(2-chloroethyl)piperazines, which could be further reacted with various nucleophiles, again under microwave irradiation conditions, to give an array of 4-substituted 1-heteroarylpiperazines in good to excellent yields. 相似文献
10.
Sandra Jiménez-Alonso Haydee Chávez Ana Estévez-Braun Ángel G. Ravelo Gabriela Feresin 《Tetrahedron》2008,64(37):8938-8942
The synthesis of novel pyrano embelin derivatives has been achieved through domino Knoevenagel hetero Diels-Alder reactions of embelin (1) with paraformaldehyde and electron rich alkenes. This synthetic approach is highly efficient when microwave irradiation is used. 相似文献
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<正>A facile and efficient method for the preparation of 2-non-substituted quinoline-4-carboxylic acids is described via the Pfitzinger reaction of isatins with sodium pyruvate following consequent decarboxylation under microwave irradiation. 相似文献
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14.
Young Seob Song 《Tetrahedron letters》2005,46(36):5987-5990
The Suzuki-Miyaura coupling reaction of α-bromocycloalkenones with arylboronic acids has been developed by using microwave heating. This method provides a simple and rapid construction of small molecule libraries of α-arylcycloalkenones with high efficiency. 相似文献
15.
Shujiang Tu Fang Fang Tuanjie Li Songlei Zhu Xiaojing Zhang 《Journal of heterocyclic chemistry》2005,42(4):707-710
A series of pyrimidoquinoline derivatives were synthesized through one‐pot condensation of 2,6‐diaminopyrimidin‐4‐one, aldehyde and cyclic a 1,3‐dicarbonyl compound in glycol under microwave irradiation without catalyst. The protocol in the absence of catalyst has the advantage of good yield (87‐95%), short reaction time (4‐7 min) and an environmentally friendly technique. 相似文献
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A rapid synthesis of N-substituted pyrroles has been described by the reaction of 4-hydroxyproline with isatins in ionic liquid under microwave irradiation. The recovered ionic liquid was reused for six cycles. The reaction proceeds without the addition of any acid promoter 相似文献
18.
A rapid and efficient method was established for the synthesis of indoloquinolinone and its analogues using acid-promoted cyclization in the present of PPA. All the reactions were completed in good yields in lOmin under microwave irradiation. 相似文献
19.
Najmadin Azizi Elahm Gholibeglo Sanaz Dehghan Nayeri 《Monatshefte für Chemie / Chemical Monthly》2012,37(8):1171-1174
Abstract
Multicomponent reactions with ultrasonic activation have been used as a simple, rapid, atom economic, and green method for the synthesis of dithiocarbamate derivatives in water. The one-pot, three-component condensation of primary and secondary amines with carbon disulfide and unsaturated carbonyl compounds or alkyl halides under ultrasonic irradiation was developed as a green and fast protocol for the rapid high-yielding preparation of dithiocarbamates in water. 相似文献20.
Kumaran G. Sreejalekshmi 《Tetrahedron letters》2006,47(35):6179-6182
An efficient synthesis of 2,4-diamino-5-ketothiazoles under solid phase conditions has been achieved by the reaction of polymer supported amidinothioureas with α-haloketones. This novel synthetic approach involving traceless cleavage from the support is suited for automation, and allows solid phase combinatorial synthesis of 2,4-diamino-5-ketothiazoles in good yields and purities. 相似文献