共查询到20条相似文献,搜索用时 15 毫秒
1.
An efficient and straightforward synthesis of furo[3,2-c]coumarins via the one-pot three-component condensation of aromatic aldehydes, 4-hydroxycoumarin and α-chloroketones in refluxing n-propanol is described. Pyridine or a mixture of AcOH and AcONH4 was used as a basic catalyst. 相似文献
2.
A new class of 2-arylamino-dihydroxyindenopyrroles were prepared by the one-pot multicomponent reaction of ninhydrin, N-methyl-1-(methylthio)-2-nitroethenamine and aromatic amines in EtOH at room temperature. The advantages of this procedure are short reaction times, good to high yields, easy separation of products and good functional group tolerance. 相似文献
3.
The treatment of 8-propargyloxy-benzo[f]coumarin with boron trifluoride diethyl etherate in N,N-dimethylformamide under reflux or MW irradiation resulted in pyrano[3,2-h]benzo[f]coumarin, while the furo[3,2-h]benzo[f]coumarin is received from the treatment with N-methylformamide under MW irradiation. 相似文献
4.
Suman Pal Md. Nasim KhanShaik Karamthulla Sk Jahir AbbasLokman H. Choudhury 《Tetrahedron letters》2013
A novel one pot protocol has been developed to synthesize various spiro[indoline-3,4′-pyrano[2,3-c]pyrazole]-3′-carboxylate derivatives from the four-component reaction of isatin, malononitrile, hydrazine derivatives and dialkyl acetylenedicarboxylates. In this process two C–C bonds, two C–N bonds and one C–O bond have formed in one pot. The notable features of this protocol are simple and environmentally benign reaction condition, easy isolation of products, applicable to a wide range of readily available starting materials and good yields. 相似文献
5.
Abbas Ali Esmaeili Hamid VesalipoorRahele Hosseinabadi Alireza Fakhari ZavarehMohammad Ali Naseri Ebrahim Ghiamati 《Tetrahedron letters》2011,52(38):4865-4867
The zwitterions generated from pyridine and dialkyl acetylenedicarboxylate (DAAD) reacted with benzofuran-2,3-diones to form highly substituted spiro pyrido[2,1-b][1,3]oxazines in good to high yields without using a catalyst. 相似文献
6.
Eleni Dimitriadou Julia Stephanidou-Stephanatou Constantinos A. Tsoleridis Dimitra J. Hadjipavlou-Litina Christos Kontogiorgis George E. Kostakis 《Tetrahedron》2014
A new aspect concerning chromone chemistry leading to the one-pot synthesis of functionalized novel ABCD-fused chromenopyrazolopyridines has been described. The synthesis involves a multicomponent reaction of chromone-3-benzoylhydrazones with isocyanides and acetylenedicarboxylates, whereupon novel complex tetracyclic benzopyrone derivatives containing three stereogenic centres were formed. The structure elucidation of the products was accomplished by 1D and 2D NMR experiments and confirmed by X-ray crystallographic analysis. Full assignment of all 1H and 13C NMR chemical shifts has been unambiguously achieved. The reaction mechanism is also discussed. In addition, eight chromenopyrazolopyridine derivatives were tested for possible biological activity (antioxidant and lipid peroxidation inhibition). 相似文献
7.
Protonation of the reactive intermediates produced in the reaction between tert-butyl isocyanide and dialkyl acetylenedicarboxylates by aromatic carboxylic acids leads to vinylnitrilium cations, which undergo nucleophilic reaction with conjugate bases of the carboxylic acids to produce dialkyl (E)-2-[(benzoyloxy)(tert-butylimino)methyl]-2-butenedioates and this intermediate rearranges to the dialkyl (E)-2-{[benzoyl(tert-butyl)amino]carbonyl}-2-butenedioate derivatives. 相似文献
8.
The domino Knoevenagel hetero-Diels-Alder reaction of the O-propargylated salicylaldehydes and 4-hydroxycoumarin leads to pyrano[2,3-c]coumarins 3 and pyrano[2,3-c]chromones 4 in high yield in the presence of CuI as a Lewis acid. In all cases, the reaction was shown to exhibit high regioselectivity and form product 3 as main product. 相似文献
9.
The regioselective three-component condensation reaction of 2-hydroxy-1,4-naphthoquinone with isocyanides in the presence of a variety of aldehydes offers an easy one-pot access to linear naphtho[2,3-b]-furan-4,9-dione derivatives. This method has the advantage of good yields, high regioselectivity, and uses readily accessible substrates and reagents. The elucidation of regiochemistry has been accomplished by X-ray determination of some representative compounds. 相似文献
10.
A new, high yield multicomponent reaction providing multifunctionalized pyrido[2,3-d]pyrimidines in a microwave-assisted one-pot cyclocondensation of α,β-unsaturated esters, amidine systems and malononitrile (or ethyl cyanoacetate) is described (the ‘Victory’ reaction). 相似文献
11.
A novel one-pot three-component reaction of 6-amino-uracil, isatin, and acetophenone was accomplished through a programmed pH variation for the synthesis of 5-(2-oxoindolin-3-yl)-1H-pyrrolo[2,3-d]pyrimidine-2,4(3H,7H)-dione derivatives. The reaction was conducted in a sequential tandem manner to give the oxindole substituted pyrrolo[2,3-d]pyrimidine products in good to excellent yields. Despite of timing all the processes were carried out in one pot. Most of these novel compounds show narrow to good spectrum of antimicrobial activities in vitro. 相似文献
12.
Microwave-assisted three-component cyclocondensation of barbituric acids 1, benzaldehyde 2 and alkyl nitriles 3 proceeds in the absence or presence of triethylamine to afford pyrano[2,3-d]pyrimidines 4 and 6-aminouracils 5 or 6-hydroxyaminouracils 6 react with 2 and 3 under identical conditions to yield pyrido[2,3-d]pyrimidines 7, all in high yields. 相似文献
13.
Priyabrata RoyBinay K. Ghorai 《Tetrahedron letters》2011,52(2):251-253
A new route for the synthesis of furo[2,3-h]quinoline and furo[2,3-h]isoquinoline derivatives have been explored through the coupling of carbene complexes with pyridine-bridged enynes. This reaction process, involving the annulation of both furan and benzene ring on to a pre-existing pyridine ring is highly efficient in the presence of triphenylphosphine as ligand additive. 相似文献
14.
A mild and efficient method for the synthesis of 1H-chromeno[2,3-d]pyrimidine-5-carboxamide derivatives via a one-pot, three-component reaction of an isocyanide, barbituric acid, and a salicylaldehyde in the presence of acetic acid in ethanol/water mixture at 75 °C is reported. This high atom economy reaction led to the construction of one benzopyran ring, and one amide group in a single synthetic step. 相似文献
15.
Ahmad Shaabani Afshin Sarvary Ali Hossein Rezayan Sajjad Keshipour 《Tetrahedron》2009,65(17):3492-1644
The three-component reaction of the zwitterions generated from dialkyl acetylenedicarboxylate and isocyanides with 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one is described. The reaction afforded the corresponding special type of fully substituted pyrano[2,3-c]pyrazole derivatives in good yields without using any catalyst and activation. 相似文献
16.
Protonation of the highly reactive 1:1 intermediate produced in the reaction between alkyl or aryl isocyanides and electron-deficient acetylenic esters with 3,6-dihydroxypyridazine, leads to a vinylisonitrilium cation, which undergoes an addition reaction with the conjugate base of the 3,6-dihydroxypyridazine to produce dialkyl 3-(alkyl or arylamino)-5,8-dioxo-5,8-dihydro-1H-pyrazolo[1,2-a]pyridazine-1,2-dicarboxylates in good yields at room temperature. 相似文献
17.
Mohammad Bagher Teimouri 《Tetrahedron》2006,62(47):10849-10853
Protonation of the highly reactive 1:1 intermediate produced in the reaction between alkyl isocyanides and electron-deficient acetylenic esters with phthalhydrazide, leads to a vinylisonitrilium cation, which undergoes an addition reaction with the conjugate base of the phthalhydrazide to produce dialkyl 3-(alkylamino)-5,10-dioxo-5,10-dihydro-1H-pyrazolo[1,2-b]phthalazine-1,2-dicarboxylates in fairly good yields at room temperature. 相似文献
18.
A one-pot two-component synthesis of tricyclic pyrano[2,3-b]quinoxalines with a pendant hydroxymethyl fuction at the 2-position relevant to molybtopterin is described by the reaction of o-phenylenediamine and phenylhydrazone derivatives of sugars in good yields. 相似文献
19.
We developed an efficient and simple one-pot synthesis of functionalized multi-substituted 2,4-dihydro-pyrano[2,3-c]pyrazole dicarboxylates from β-ketoesters, hydrazine, dimethyl acetylenedicarboxylate and malononitrile in EtOH. This four-component one-pot reaction carried out in the presence of DABCO catalyst showed advantages over a one-pot three-component method in its simple procedure, high yield and low toxicity. 相似文献
20.
Vijay Nair Rajeev S. Menon Ani Deepthi B. Rema Devi A.T. Biju 《Tetrahedron letters》2005,46(8):1337-1339
Isocyanides, dimethyl acetylenedicarboxylate, and cyclobutene-1,2-diones react in one-pot to afford novel spirocyclic compounds with double insertion of the isocyanide. 相似文献