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1.
Imino Diels-Alder reaction of imines with 2,3-dihydrofuran or 3,4-dihydro-2H-pyran proceeded smoothly in the presence of a catalytic amount (0.5 mol %) of ytterbium triflate to afford furo[3,2-c]- and pyrano[3,2-c] quinolines conveniently in high yield. 相似文献
2.
Narsidas J. Parmar Shashikant B. TeraiyaRikin A. Patel Navin P. Talpada 《Tetrahedron letters》2011,52(22):2853-2856
A tetrabutylammonium hydrogen sulfate (TBA-HS) mediated procedure for one pot synthesis of novel benzopyran-annulated pyrano[2,3-c]pyrazoles via domino/Knoevenagel-hetero-Diels-Alder reaction has been demonstrated. 相似文献
3.
A series of substituted pyrano[2,3-c]pyrazole derivatives were synthesized by a one-pot reaction of methyl 4-methyl-3-oxovalerate, phenylhydrazine, aromatic aldehyde, and malononitrile in ethanol with catalysis by triethylamine. The title compounds were obtained in good to excellent yields. A possible mechanism for this reaction was proposed. 相似文献
4.
The present work describes eco-friendly multicomponent protocol for the synthesis in excellent yields of structurally diverse benzylpyrazolyl coumarin 5 (a–s) involving the reaction of 4-hydroxycoumarin, ethyl acetoacetate, hydrazine hydrate/phenyl hydrazine hydrate and aldehydes, also novel pyrano[2,3-c]pyrazole derivatives 8 (a–k) integrated by isonicotinic acid hydrazide from reaction of aldehyde, ethyl acetoacetate, malononitrile with isoniazid, employing water as a reaction medium and 2-aminoethanesulfonic acid (taurine) as the catalyst. This new methodology endowed the advantages such as short reaction time, recovery of catalysts after catalytic reaction and reusing them without losing their activity and alleviate of operation. 相似文献
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6.
《应用有机金属化学》2017,31(11)
Superparamagnetic nanoparticles of modified thioglycolic acid (γ‐Fe2O3@SiO2‐SCH2CO2H) represent a new, efficient and green catalyst for the one‐pot synthesis of novel spiro[benzo[a ]benzo[6,7]chromeno[2,3‐c ]phenazine] derivatives via domino Knoevenagel–Michael–cyclization reaction of 2‐hydroxynaphthalene‐1,4‐dione, benzene‐1,2‐diamines, ninhydrin and isatin. This novel magnetic organocatalyst was easily isolated from the reaction mixture by magnetic decantation using an external magnet and reused at least six times without significant loss in its activity. The catalyst was fully characterized using various techniques. This procedure was also applied successfully for the synthesis of benzo[a ]benzo[6,7]chromeno[2,3‐c ]phenazines. 相似文献
7.
《中国化学会会志》2017,64(6):690-698
An efficient and green strategy for the improved synthesis of a biologically and pharmaceutically interesting multi‐functionalized diverse novel spiro‐benzo[a ]phenazine annulated heterocycles was developed with the assistance of microwave irradiation. A sequential one‐pot, two‐step domino reaction starting from 2‐hydroxynaphthalene‐1,4‐dione, benzene‐1,2‐diamines, a cyclic carbonyl compound, and 1,3‐indandione in the presence of a basic ionic liquid (1‐butyl‐3‐methylimidazolium hydroxide) as an expedient, ecofriendly and reusable catalyst afforded the corresponding novel spiro[benzo[a ]indeno[2′,1′:5,6]pyrano[2,3‐c ]phenazine] derivatives with high yield under solvent‐free conditions. This domino Knoevenagel–Michael annulation reaction provided five new bonds (two C–C, two CN, and one C–O) and two new rings through multiple operations in a single flask. 相似文献
8.
Razieh Mohebat Afshin Yazdani-Elah-Abadi Malek-Taher Maghsoodlou Nourallah Hazeri 《中国化学快报》2017,28(5):943-948
An efficient, convenient and environmentally benign procedure for the synthesis of novel 3-oxo-3H-benzo[a]pyrano[2,3-c]phenazine-1-carboxylate and 3-(5-hydroxybenzo[a]phenazin-6-yl)acrylate derivatives has been developed by domino three-component condensation reaction between 2-hydroxynaphthalene-1,4-dione, benzene-1,2-diamines and acetylenic esters in the presence of a catalytic amount of DABCO as an expedient, eco-friendly and reusable base catalyst in water. This green process produces biologically and pharmacologically significant heterocycles in a one-pot single operation and offers considerable advantages such as:operational simplicity, short reaction time, high yields, reusability of catalyst, absence of any tedious workup or purification and avoids hazardous reagents/solvents. 相似文献
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Synthesis of pyrimido[1,2-a]benzimidazole and pyrano[2,3-c]pyrazole derivatives were achieved using polyethylene glycol (PEG-400) as promoting reaction medium in water under catalyst-free conditions at reflux and room temperature, respectively. The structure of pyrimido[1,2-a]benzimidazole was confirmed using 1H NMR, 13C NMR, DEPT, and HMBC experiments. The promising points for the present methodology are efficiency, generality, high yield, short reaction time, cleaner reaction profile, ease of product isolation, simplicity, potential of recycling reaction medium, and finally agreement with green chemistry protocols. 相似文献
11.
An efficient and practical route to novel fluorescent benzo[a]pyrano[2,3-c]phenazine framework has been developed by one-pot, four-component reaction of 2-hydroxynaphthalene-1,4-dione, 1,2-phenylenediamines, aromatic aldehydes, and Meldrum’s acid in glacial acetic acid at 70 °C. Photophysical studies of these compounds have been reported. Reactions involving cyclohexane-1,3-dione/5-methylcyclohexane-1,3-dione/dimedone in the place of Meldrum’s acid yielded corresponding benzo[a]chromeno[2,3-c]phenazine derivatives. Crystal structure of 3k established the regioisomer formed. Mild reaction conditions, good yields, short reaction time, and easy separation are some of the salient features of the present protocol. 相似文献
12.
The base promoted four-component reaction of hydrated hydrazine, dimethyl acetylenedicarboxylate, isatines and malononitrile (ethyl cycanoacetate) in ethanol afforded polysubstituted spiro[indoline-3,4‘-pyrano[2,3-c]pyrazoles] and spiro[acenaphthyl-3,4-pyrano[2,3-c]pyrazoles] 相似文献
13.
One-pot synthesis of pyrano[2,3-c]pyrazole derivatives via two or multicomponent condensation of β-ketoesters, hydrazine monohydrate/phenyl hydrazine, malononitrile, and substituted benzaldehydes is of great interest not only in synthetic chemistry but also in medicinal chemistry because of the tremendous biological activities, such as anticancer, anti-inflammatory, analgesic, antimicrobial, and enzyme inhibitory activities exhibited by pyranopyrazoles. This review provides extensive knowledge on novel synthetic methodologies of biologically active non-spiro/spiro-pyrano[2,3-c]pyrazole derivatives published recently. 相似文献
14.
A. M. Kamal El-Dean M. S. A. El-Gaby A. M. Gaber H. A. Eyada A. S. N. Al-Kamali 《Phosphorus, sulfur, and silicon and the related elements》2013,188(2):413-424
Abstract Novel series of thieno[2,3-c]pyridazines and pyrimido[4′,5′:4,5] thieno-[2,3-c]pyridazines have been synthesized from the readily accessible 4-cyano-5,6-dimethylpyridazin-3(2H)-thione 3b. 相似文献
15.
S. V. Tolkunov M. N. Kal'nitskii E. A. Zemskaya 《Chemistry of Heterocyclic Compounds》1991,27(11):1253-1256
The reaction of 1,7-dimethyl-3(2H)-benzo[b]furo[2,3-c]pyridone with phosphoric acid amides gave 1,7-dimethyl-3-dimethylamino (morpholino)benzo[b]furo[2,3-c]pyridines. A method for the synthesis of 3-amino derivatives of 4-nitrobenzo[b]furo[2,3-c]pyridines, which consists in heating 1,7-dimethyl-4-nitro-3(2H)-benzo[b]furo[2,3-c]pyridone with hexamethyldisilazane and secondary or primary amines in pyridine, was developed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1552–1555, November, 1991. 相似文献
16.
An efficient, high-yielding, and rapid protocol has been developed for the synthesis of diversity-oriented 6-amino-2,4-dihydropyrano[2,3-c]pyrazol-5-carbonitriles derivatives via a four-component, one-pot cyclocondensation reaction of ethyl acetoacetate, hydrazine hydrate, aldehydes, and malononitrile using silica-supported tetramethylguanidine as a heterogeneous catalyst for the first time. The protocol proves to be efficient and environmentally benign in terms of very easy workup, good yields, and ease of recovery of catalyst. In addition, the present method is superior in terms of green media, the amount of catalyst, and reaction time. 相似文献
17.
Olga Ya. Shyyka Roman L. Martyak Mykola A. Tupychak Nazariy T. Pokhodylo Mykola D. Obushak 《合成通讯》2017,47(24):2399-2405
Convenient two-step procedure for the synthesis of fused chromenone derivatives was developed. Reduction of the obtained in the Meerwein arylation reaction aryl- and thienylquinones allowed to construct 6H-benzo[c]chromene-6-ones and 4H-thieno[2,3-c]chromen-4-one in a more cost- and time-effective manner in comparison with already known methods. The obtained products have provided a new entry to chromenone derivatives. 相似文献
18.
An efficient one-pot synthesis of 6-amino-4-(2-chloroquinolin-3-yl)-3-methyl-2, 4-dihydro-pyrano[2,3-c]pyrazole-5-carbonitrile derivatives (4a–f)(5a–f) by three component reactions of 2-chloroquinolin-3-carbaldehyde derivatives, malanonitrile, and 3-methyl pyrazolin-5-one derivatives catalyzed by L-proline in ethanol medium under mild conditions is established. The synthesized compounds were evaluated for antimalarial activity and the LC50/LC90 values were described. Compounds 4d, 5d, and 5f exhibits good antimalarial activity when compared to other pyrano[2,3-c]pyrazole scaffolds. 相似文献
19.
S. V. Tolkunov A. I. Khizhan S. I. Simonova N. S. emenov S. N. Lyashchuk 《Chemistry of Heterocyclic Compounds》1994,30(3):283-288
Summary Condensation of benzo[b]furan-3(2H-one, benzo[b]thiophen-3(2H)-one and benzo[b]selenophen-3(2H)-one with dimedone gives 2-(3-heteryl)dimedones. Acylation of the latter leads to the corresponding tetracyclic pyrylium salts, from which condensed quinolines are obtained. Some condensed quinoline derivatives are obtained by reaction of 1-oxo-1,2,3,4-tetrahydroheterene[2,3-c]quinolines with sodium borohydride, hydrazine, and hydroxylamine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 321–326, March, 1994. 相似文献