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1.
Stereospecific syntheses, from Δ-3-chromene, of cis and trans-4-aminochroman-3-ols, 5 and 8 , and their conversion into cis and trans-1,2,3,4a,5,10b-hexahydro[1]benzopyrano[3,4-b][1,4]-oxazines, 15 and 16 , are described. 相似文献
2.
Synthesis of 1,2,3,4-tetrahydro-5H-[1]benzopyrano[3,4-c]pyridin-5-ones. I. 3-unsubstituted compounds
David T. Connor Paul C. Unangst Charles F. Schwender Roderick J. Sorenson Mary E. Carethers Chester Puchalski Richard E. Brown 《Journal of heterocyclic chemistry》1984,21(5):1557-1559
Synthesis of 1,2,3,4-tetrahydro-5H-[1]benzopyrano[3,4-c]pyridin-5-ones via a Pechmann condensation of 3-carbethoxy-1-methyl-4-piperidone with various phenols is described. The limitations of this method are discussed. Synthesis of the parent ring system 3a via reduction of 1,2,3,4-tetrahydro-3-(phenylmethyl)-8-[(1-phenyl-1H-tetrazol-5-yl)oxy]-5H-[1]benzopyrano[3,4-c]pyridin-5-one ( 5 ) is also described. 相似文献
3.
When equimolar quantities of salicylaldehyde 2 and ethyl 3-amino-2-butenoate 3 or its constituents (ethyl 3-oxobutanoate and ammonia) were refluxed on a steam-bath for 6 hours with a trace of acetic acid, two products, a pentacyclic pyridine dilactone 4 and 3-acetyl coumarin 5 , resulted in 15% and 45% yields, respectively. The structure of 4 was elucidated as 7-methyl[1]benzopyrano[4,3-d][1]benzoxacino[4,3-b]-pyridine-6,16-dione on the basis of its spectral data. The mechanism of its formation has been discussed. The reaction has been extended to three more substituted salicylaldehydes. 相似文献
4.
Misbahul Ain Khan Maria Lucia De Brito Morley 《Journal of heterocyclic chemistry》1978,15(8):1399-1401
The diazotization of 3-aminocoumarin followed by its reduction gave the cournarin-3-yl-hydrazine which, without isolation, reacted with various carbonyl compounds in a Fisher's indohzation reaction to give derivatives (Ib-Ih) of the yet unreported system 3H,4H[1]benzopyrano[3,4-b]pyrrol-4-one. 相似文献
5.
Egle M. Beccalli 《Tetrahedron》2005,61(21):4957-4964
The synthesis of [1]benzopyrano[4,3-b]pyridin-5-ones 4a-f and 4g-j starting from 3-formylcoumarin and 3-cyanocoumarin N-functionalized amidines 3a-f and 3g-j, respectively, was reported. The ring-closure reaction mechanism, under basic or acidic media, was proposed. Furthermore, the reaction of 3-formylamidines 3a,c-f with ammonium acetate gave good yields of 2-substituted [1]benzopyrano[4,3-d]pyrimidin-5-ones 7. 相似文献
6.
Under basic conditions. [1]benzopyrano[2,3-b]quioxakin-12-one leads to 3-(i-hydroxybenzoy1)-1H-quinoxalin-2-one. This ketone reacts with hydroxylamine and phenylhydrazine to give the expected derivatives or those of [1]benzopyrano92,3-b]quinoxalin-12-one. The reduction of [1]benzopyrano[2,3-b]quinoxalin-12-one was unsucessful by chemical means. However, electrochemical reduction leads to a dihydropyrazine nucleus. 相似文献
7.
Egle M. Beccalli 《Tetrahedron letters》2004,45(17):3447-3449
A new synthesis of [1]benzopyrano[4,3-b]pyridin-5-ones 4 was developed starting from 3-formyl-coumarin N-functionalized amidines 3. The reaction is based likely on the intramolecular cyclocondensation of the C-α amidinic carbanion in basic medium on the formyl group. 相似文献
8.
3-Aminocoumarin undergoes the Skraup reaction to give a new ring system, 5H[l]benzo-pyrano[3,4-b]pyridin-5-one (IVa). When 3-aminocoumarin was condensed with the ethoxy methylene derivatives of active methylene compounds, ethyl acetoacetate, and dimethyl acetylenedicarboxylate, the intermediates Vla-VIf were formed which on thermal cyclizations afforded other derivatives of 5H[l ]benzopyrano[3,4-b]pyridin-5-one (IVb-IVf). The nitration of IVa gave IVg. 相似文献
9.
Albert Lvai 《Journal of heterocyclic chemistry》1998,35(1):13-16
Stereoselective synthesis of trans-2,3,3a,4-tetrahydro-3-aryl-2-phenyl[1]benzopyrano[4,3-c]pyrazoles 13–18 and their [1]benzothiopyrano analogues 19–24 has been performed by the reaction of 3-arylidenechromanones 1–6 and 3-arylidene-1-thiochromanones 7–12 with phenylhydrazine in hot pyridine. The structure and stereochemistry of the compounds prepared have been elucidated by ir, lH and 13C nmr measurements. 相似文献
10.
C. K. Ghosh 《合成通讯》2013,43(7):487-490
For our synthetic work we needed the title compound. Literature survey revealed that 2-amino-4-oxo-4H-[1] benzopyran-3-carboxaldehyde (2-amino-3-formylchro-mone) can undergo condensation with diethyl malonate (or ethyl cyanoacetate) forming ethyl 2-hydroxy(or amino)-5-oxo-5H-[1]benzopyrano[2,3-b]pyridine-3-carboxylate1. 相似文献
11.
Starting from 7-alkoxy-4-aminocoumarins 5,6,8,12 , and 13 as key intermediates, this paper describes two different methods for the preparation of azacannabinoidal 5H[1]benzopyrano[4,3-b]pyridin-5-ones 24–27, 38 , and 39 containing typical structural requirements for ZNS activity. First, Michael addition of 6 and 8 to the double bonds of alkyl vinyl ketones 14 and 15 resulted in a mixture of tetrahydropyridines 24–27 and fused pyridines 20–23 the latter of which were reduced by sodium cyanoborohydride to give the target compounds 24–27 . The second, pyridine ring closure was accomplished by a combination of Vilsmeier acetylation and formylation resulting in fused 4-chloropyridines 31–33 followed by reduction. 相似文献
12.
Halochromic Molecules. Substituted 6,11-Dihydrospiro[[1]benzopyrano[4,3-b]indol-6,9′-9′H-xanthene]-2′,6′-diamines and Their Aza Analogues: New Chromogenes for Black Images . We have synthesized a series of substituted 6,11-dihydrospiro[[1]benzopyrano[4,3-b]indo1-6,9′-9′H-xanthene]-2′,6′-diamines and their respective aza analogues. These compounds develop a black colour in acidic media. The assumed structures of the analytically pure starting and final products are consistant with the fragmentations in the MS and are also supported by FT 1H-NMR. The UV/VIS spectra in buffered MeOH/H2O solutions were measured. From the ?pH* curves, we determined the pK* values. The title compounds can be used in so-called pressure-sensitive copying systems. 相似文献
13.
V. L. Savel'ev O. L. Samsonova V. S. Troitskaya V. P. Lezina 《Chemistry of Heterocyclic Compounds》1991,27(1):108-112
4H-[1]benzopyrano[3,4-c][1,2,5]selenodiazol-4-one has been synthesized by the reaction of 3,4-diaminocoumarin with selenous acid and its reaction with several nucleophiles (alkali, ammonia, amines, hydrazine hydrate) and its nitration have been studied. Using PMR spectroscopy, a comparative kinetic study of the opening of the lactone ring in 6,8-dinitro-4H-[1]benzopyrano[3,4-c][1,2,5]seleno- and thiadiazol-4-ones has been carried out.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 128–133, January, 1991. 相似文献
14.
The fused heterocycles benzothiopyrano[2,3-b]indol-11-one and benzopyrano[2,3-b]indol-11-one, have been prepared from methyl 3-indole carboxylate in two steps. 相似文献
15.
Various trisubstituted [1]benzopyrano[4,3-b]pyrrol-4(1H)-one derivatives have been synthesized from 4-hydroxycoumarin with a 30-40% yield over six steps. The key step of the synthesis is a base-promoted intramolecular cyclization of enamines 5, followed by dehydration to generate the fused pyrrole ring. 相似文献
16.
Selected C(α),N-dilithiocarboalkoxyhydrazones were prepared in an excess of lithium diisopropylamide (LDA) and condensed with a variety of salicylate esters to give intermediates that were acid-cyclized to benzopyrano[3,4-b]pyrazoles (coumarin-pyrazoles). 相似文献
17.
Starting from 4-chlorocoumarin-3-carbaldehyde (1) and Wittig phosphoranes 2a-d the title compounds 6a-c have been synthesized via a four-step sequence. The intermediate 4-alkylamino-3-vinylcoumarins 5a-k have been prepared by the reaction of 4-chloro-3-vinylcoumarins 3a-d with primary amines 4a-h . The coumarin derivatives 5 (except 5k ) underwent an unusual pyridine ring closure under Vilsmeier conditions to form the benzopyrano[4,3-b]pyridines 6 . When the aminoaldehydes 7 were treated with the Wittig reagent 2b the fused N-alkyl-2 (1H) -pyridinones 8 have been obtained as expected. 相似文献
18.
V. A. Mamedov L. P. Sysoeva A. T. Gubaidullin A. I. Zamaletdinova I. A. Litvinov 《Russian Chemical Bulletin》2005,54(6):1539-1541
Three-component condensation of diethyl 2,4,6-trioxoheptanedicarboxylate with salicylaldehyde and ammonium acetate in EtOH
affords 2,5-diethoxycarbonyl-5-hydroxy-4-oxo-4,4a, 5,10b-tetrahydro-1H-[1]benzopyrano[4,3-b]pyridine.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1494–1496, June, 2005. 相似文献
19.
A new heterocyclic compound, [1]benzopyrano[2,3,4-kl]acridin-3-ol was synthesized by cyclization of xanthone derivatives. The key compound, 1-(3'-methoxyanilino)-xanthone, was prepared from 1-aminoxanthone. [1]benzopyrano[2,3,4-kl]acridin-3-ol analogues, [1]benzothiopyrano[2,3,4-kl]acridin-3-ol, pyrido[3',2':5,6]pyrano[2,3,4-kl]acridin-3-ol and pyrido[3',2':5,6]thiopyrano[2,3,4-kl]acridin-3-ol were synthesized by the same method. 相似文献
20.
Sanaa O. Abd Allah Hamdy A. Hammouda Fatma A. Ali 《Journal of heterocyclic chemistry》1985,22(2):497-500
5-Salicylidenethiazolidine-2,4-dithione ( 1 ) reacts with acrylonitrile, N-phenylmaleimide and dimethyl acet-ylenedicarboxylate to afford the fused thiopyrano[2,3-d]thiazolidinethione derivatives 2, 4 and 6 , respectively. The salicylidene derivative 1 reacts with ethyl acrylate and malononitrile to afford the fused [1]benzopyrano[3′,4′:4,5]thiopyrano[2,3-d]thiazoles 3 and 9 , respectively. 4-Phenylhydrazono-2-thiazolidinethione ( 11 ) reacts with ethyl bromoacetate and/or phenacyl bromide to yield the fused thiazolo[3,4-c]triazines 13 and 14. 相似文献