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1.
We have reported DBU catalyzed one-pot synthesis of 3,4-dihydropyrano[3,2-c]chromenes, dihydropyrano[4,3-b]pyranes, 2-amino-4H-benzo[h]chromenes and 2-amino-4H-benzo[g]chromenes from aldehydes, active methylene compounds malononitrile/ethyl cyanocacetate, and 4-hydroxycoumarin/4-hydroxy-6-methylpyrone/1-naphthol/2-hydroxynaphthalene-1,4-dione in water under reflux. The attractive features of this process are mild reaction conditions, reusability of the reaction media, short reaction times, easy isolation of products, and excellent yields. 相似文献
2.
Manohar Mantipally Rambabu Gundla Madhusudhana Reddy Gangireddy Viswanathan Vijayan Velmurugan Devadasan 《Tetrahedron letters》2018,59(52):4616-4619
A novel method for the synthesis of 2-imino-2H-benzo[h]chromenes via the sequential addition of N-chlorosuccinimide and triethylamine to 2-amino-4H-benzo[h]chromenes has been established. This reaction protocol represents an efficient synthetic strategy to form iminochromene derivatives under mild reaction conditions, which utilizes readily accessible aminochromenes as starting materials and tolerates a wide range of substrates. 相似文献
3.
E.G. Frandsen 《Tetrahedron》1977,33(8):869-873
The reaction of 4- and 5-aryl-3-methylthio-1,2-dithiolylium iodides with 4-hydroxy-6-methyl-2-pyran-2-one and 4-hydroxycoumarin has been studied. 4-Substituted salts yielded 3-aryl-7-methyl-2-thioxo-2,5-pyrano [3,2-c]pyran-5-ones and 3-aryl-2-thioxo-2H,5H-pyrano[3,2-c]benzo[e]pyran-5-ones, respectively, whereas 5-substituted salts gave rise to 3-(5′-aryl-1′,2′-dithiol-3′-ylidene)-6-methyl-2-pyran-2,4-diones and 3-(5′-aryl-1′,2′-dithiol-3′-ylidene)-2-benzo [b]-pyran-2,4-diones. 相似文献
4.
Yu. V. Popova D. V. Osipov V. A. Osyanin Yu. N. Klimochkin 《Russian Journal of Organic Chemistry》2017,53(4):599-603
The condensation of trifluoroacetyl-substituted 4H-chromenes and 1H-benzo[f]chromenes with 6-amino-1,3-dimethyluracil and 6-aminothiouracil afforded a number of pyrido[2,3-d]pyrimidine derivatives containing a 2-hydroxybenzyl or 2-hydroxynaphthalen-1-ylmethyl group in the 6-position as a result of cascade transformation initiated by Michael addition. 相似文献
5.
A highly efficient palladium-catalysed phenyl diazonium tetrafluoroborate participation of C–H activation ring closure protocol has been developed. A series of 6H-benzo[c]chromenes have been synthesized by intramolecular cyclization of ortho diazonium salts tetrafluoroborate of benzyloxyphenyl (Method A), or phenoxymethyl phenyl (Method B). The transformation allows the synthesis of 6H-benzo[c]chromenes with a wide variety of functional groups and substitution patterns from simple and easily accessible precursors. 相似文献
6.
Organocatalytic domino oxa-Michael-Michael-Michael-aldol condensation of 2-((E)-2-nitrovinyl)phenol and 2 equiv of α,β-unsaturated aldehydes (e.g., cinnamaldehyde) provided tetrahydro-6H-benzo[c]chromenes in high diastereoselectivity and high enantioselectivity (>99% ee). Structure of the adduct 4a was confirmed unambiguously by X-ray analysis. The diversity of the protocol was demonstrated by the chemo-differentiating three-component reactions (ABC type) affording the highly functionalized tetrahydro-6H-benzo[c]chromenes. 相似文献
7.
Highly efficient regioselective protocol for the synthesis of hitherto unreported 4H-benzo[f]chromenes has been developed by one-pot four-component coupling of aromatic aldehydes, β-naphthol, β-oxodithioesters, and primary alcohols in the presence of InCl3. This transformation presumably proceeds via domino Knoevenagel condensation/Michael addition/intramolecular cyclodehydration/transesterification sequence creating four new bonds and one stereocenter in a single operation. Further, alcohol plays dual role as a reactant as well as reaction medium. 相似文献
8.
Liangce Rong Shimin Tao Sheng Xia Lihua Liu Shan Yin Yanhui Shi 《Research on Chemical Intermediates》2012,38(7):1647-1654
An efficient and convenient multicomponent reaction for preparation of 2-amino-4-aryl-6,7,8,9-tetrahydro-5H-benzo[7]annulene-1,3-dicarbonitrile derivatives, in THF, with DBU as catalyst is reported. These compounds are typical acceptor–donor–acceptor (A–D–A) systems comprising one electron donor and two electron acceptors with different important chemical properties. Excellent yields and the simplicity of the reaction procedure make this one of the most efficient methods for synthesis of these types of compound. 相似文献
9.
Yueteng Zhang Peng Ji Xiang Meng Feng Gao Fanxun Zeng Wei Wang 《Molecules (Basel, Switzerland)》2021,26(12)
A simple arylamine-catalyzed Mannich-cyclization cascade reaction was developed for facile synthesis of substituted 2H-benzo[h]chromenes. The notable feature of the process included the efficient generation of ortho-quinone methides (o-QMs) catalyzed by a simple aniline. The mild reaction conditions allowed for a broad spectrum of 1- and 2-naphthols and trans-cinnamaldehydes to engage in the cascade sequence with high efficiency. 相似文献
10.
Mohammad Sadegh Asgari Mehdi Soheilizad Parviz Rashidi Ranjbar Bagher Larijani Rahmatollah Rahimi Mohammad Mahdavi 《Tetrahedron letters》2019,60(8):583-585
An efficient approach for the synthesis of N-alkyl-2-aryl-2-(6-oxo-4H-benzo[f][1,2,3]triazolo[1,5-a][1,4]diazepin-5(6H)-yl)acetamides is described. The protocol involves Ugi four-component reaction of 2-bromobenzoic acid, propargylamine, aldehydes and isocyanides followed by in situ sequential click reaction of azide ion with triple bond and N-arylation reaction to afford desired products in good to excellent yields. 相似文献
11.
AbstractWe report herein a new method for the synthesis of 4-aryl-3,4-dihydro-2H-benzo[g]chromene-2,5,10-triones 4 that proceeds in good yields (74–86%) and mild reaction conditions between readily available 2-amino-4-aryl-5,10-dioxo-5,10-dihydro-4H-benzo[g]chromene-3-carbonitriles 1, and formic acid (88%), at reflux for 6?h. In addition, we have also studied the antioxidant activities using DPPH and total TAC methods. 相似文献
12.
Qing Qing Meng He Xiang Bai Feng Li Quan Rui Wang Feng Gang Tao 《中国化学快报》2007,18(7):785-787
A convenient synthetic pathway to 2-aryl-5,6-dihydro-4H-benzo[f][1,2,4]triazolo[1,5-α]azepine derivatives 7 was developed. The synthesis was based on the cycloaddition of the 1,2,3,4-tetrahydronaphthalene a-acetoxy azo compounds 3 with Ar-CN in the presence of AlCl3 and the consecutive ring enlargement. 相似文献
13.
Abolfazl Olyaei Mohammad Sadegh Shahsavari Mahdieh Sadeghpour 《Research on Chemical Intermediates》2018,44(2):943-956
An efficient tandem reaction approach is described to prepare novel benzo[f]chromenes from 2,3-dihydroxynaphthalene, malononitrile and aldehydes using 10 mol% guanidine hydrochloride as the catalyst under solvent-free conditions. The method was also extended to the preparation of novel 12H-benzo[5,6]chromeno[2,3-b]pyridines from 2-aminoprop-1-ene-1,1,3-tricarbonitrile instead of malononitrile under the same reaction conditions. The described one-pot three-component reaction is characterized by short reaction times, high-product yield, mild reaction conditions, simple workup procedure, and simple purification. 相似文献
14.
Ahmed M. El-Agrody Heba K. Abd El-Mawgoud Ahmed M. Fouda Essam S. A. E. H. Khattab 《Chemical Papers》2016,70(9):1279-1292
A series of 2-amino-4H-benzo[h]chromene and 2,7-diamino-4H-benzo[h]chromene derivatives were prepared as potential cytotoxic agents. The structures of the synthesised compounds were established on the basis of spectral data. The in-vitro cytotoxic activity of the synthesised compounds against the cell lines MCF-7, HCT-116 and HepG-2 was investigated in comparison with vinblastine and colchicine, using an MTT colorimetric assay. The structure-activity relationship of 4H-benzo[h]chromenes with modification at the 3-, 4- and 7-positions was explored. The results of the anti-tumour evaluation revealed that compounds VIIIc, VIId, VIIb, VIIe, VIIIg and VIIIc, VIId, VIIb, VIIe, VIIIg, VIIc, VIIIe, Vf, IIIa inhibited the growth of MCF-7 in comparison with vinblastine and colchicine, while VIIb, VIId, VIIe, IIIa, VIIa, VIIIc, VIIc, IIId, IIIg, IIIf, IIIb, IIIh, VIIIb, VIIIa, VIIIe, IIIc, Vg, IIIe, VIIIg, Vf, IIIf inhibited the growth of HCT-116 in comparison with colchicine. In addition, compounds VIIe, IIIg, IIIa, VIIc and VIIe, IIIg, IIIa, VIIc, VIIb, VIIa, VIIIf, VIIIe inhibited the growth of HepG-2 in comparison with vinblastine and colchicine, respectively. 相似文献
15.
Christian Deshayes Bernard Pujol Suzanne Gelin 《Journal of heterocyclic chemistry》1986,23(5):1415-1418
Some 5-aryl-4,5-dihydro[1]benzoxepin-3(2H)-ones and 5-aryl-5,6,8,9-tetrahydro-7H-benzocyclohepten-7-ones were synthesized by hydrogenolytic cleavage of the isoxazole ring of 4-aryl-3-oxo-3,3a,4,10-tetrahydro[1]-benzoxepino[3,4-c]isoxazoles or 4-aryl-3-oxo-3a,4,9,10-tetrahydro-3H-benzo[4,5]cyclohepta[1,2-c]isoxazoles which in turn were prepared from ethyl 3-oxo-4-phenoxybutanoate or ethyl 3-oxo-5-phenylpentanoate by simple methods. 相似文献
16.
New methods for the synthesis of (E)-3-halo-2-styryl-4H-chromen-4-ones were established. The reaction of these compounds with hydrazine hydrate afforded new and unexpected 3(5)-aryl-5(3)-[2-(2-hydroxyphenyl)-2-hydrazonoethyl]-1H-pyrazoles, which upon acid hydrolysis gave 3(5)-aryl-5(3)-[2-(2-hydroxyphenyl)-2-oxoethyl]-1H-pyrazoles. The reaction mechanisms for these transformations, involving 1,6- followed by 1,4-conjugate additions, are discussed and the structures of all new compounds were established by NMR studies. 相似文献
17.
Liqiang Wu Suying Ma Fulin Yan Chunguang Yang 《Monatshefte für Chemie / Chemical Monthly》2010,122(3):565-568
Abstract
An efficient synthesis of 4-aryl-3-methyl-1-phenyl-1H-benzo[g]pyrazolo[3,4-b]quinoline-5,10-diones from the three-component condensation reaction of 3-methyl-1-phenyl-1H-pyrazol-5-amine, aromatic aldehydes, and 2-hydroxy-1,4-naphthoquinone under solvent-free conditions in good to excellent yields and short reaction times using sulfamic acid as heterogeneous acid catalyst has been investigated. 相似文献18.
Kanaka Pattabiraman Rita El-Khouri Kriti Modi Lawrence R. McGee David Chow 《Tetrahedron letters》2009,50(14):1571-1574
Herein, we describe the synthesis of the novel 4-(1H-benzo[d]imidazol-2-yl)isoxazol-5-amine (7) and 4-(1H-benzo[d]thiazol-2-yl)isoxazol-5-amine scaffolds (8). Initial attempts following literature procedures for the synthesis of similar compounds did not yield the desired product. Instead we obtained the ring-opened adduct 2-(1H-benzo[d]imidazol-2(3H)-ylidene)-2-cyanoacetamide (5). We were able to modify reaction conditions and successfully synthesize the desired product. We also describe a convenient one-pot microwave-assisted relay reaction for the synthesis of novel and reported 2-substituted benzimidazoles and benzothiazoles from inexpensive, commercially available reagents, 2-benzothiazole acetonitrile (2) and 2-benzimidazole acetonitrile (1). In all cases, good yields of products were obtained and reaction times were significantly reduced. 相似文献
19.
V. V. Shchepin P. S. Silaichev Yu. G. Stepanyan K. P. Lebedev M. I. Vakhrin 《Russian Journal of General Chemistry》2006,76(5):743-746
Zinc enolate derived from 1,1-dibromo-3,3-dimethylbutan-2-one reacts with 3-aryl-2-cyanoprop-2-enamides and aryl 3-aryl-2-cyanoprop-2-enoates to give the corresponding derivatives of 3-aryl-2-(2,2-dimethylpropanoyl)-1-cyanocyclopropane-1-carboxylic acid as a single stereoisomer with cis arrangement of the hydrogen atoms at the cyclopropane ring. The reactions of the same zinc enolate with 3-morpholinocarbonyl-2H-chromen-2-one and 2-morpholinocarbonyl-3H-benzo[f]chromen-3-one lead to formation of 1-(2,2-dimethylpropanoyl)-1a-morpholinocarbonyl-1a,7b-dihydrocyclopropa[c]chromen-2-one and 1-(2,2-dimethylpropanoyl)-1a-morpholinocarbonyl-1a,9c-dihydrobenzo[f]cyclopropa[c]chromen-2-one, respectively as a single stereoisomer. 相似文献
20.
Earth abundant metals are much less expensive, promising, valuable metals and could be served as catalysts for the borrowing hydrogen reaction, dehydrogenation and heterocycles synthesis, instead of noble metals. The uniformly dispersed zinc composites were designed, synthesized and carefully characterized by means of XPS, EDS, TEM and XRD. The resulting zinc composite showed good catalytic activity for the N-alkylation of amines with amines, ketones with alcohols in water under base-free conditions, while unsaturated carbonyl compounds could also be synthesized by tuning the reaction conditions. Importantly, it was the first time to realize the synthesis of 2-aryl-1H-benzo[d]imidazole derivatives by using this zinc composite under green conditions. Meanwhile, this zinc catalyst could be easily recovered and reused for at least five times. 相似文献