Reactions of 5-[3-(trifluoromethyl)-phenyl]furan-2-carbaldehyde

The Knoevenagel condensations of 5-[3-(trifluoromethyl)phenyl]furan-2-carbaldehyde with seven compounds containing an active methyl or methylene group have been studied. The compounds used were: methyl 2-cyanoacetate, malononitrile, 2-furylacetonitrile, acetophenone, 2-thioxo-1,3-thiazolidin-4-one (rhodanine), 5,5-dimethylcyclohexane-1,3-dione (dimedone), and methyl 2-azidoacetate. The effect of microwave irradiation on the condensation reactions was studied and compared with “’classical”’ conditions. Thermolysis of methyl 2-azido-3-{5-[3-(trifluoromethyl)phenyl]-2-furyl}propenoate afforded methyl 2-[3-(trifluoromethyl)phenyl)]-4H-furo[3,2-b]pyrrole-5-carboxylate. (2E)-3-{ 5-[3-(Trifluoromethyl)phenyl]-2-furyl}propenoic acid was converted to the corresponding azide, which was cyclized on heating into 2-[3-(trifluoromethyl)phenyl)]-4,5-dihydrofuro[3,2-c]pyridin-4-one. The latter after successive action of POCl₃ and NH₂NH₂-Pd/C gave 2-[3-(trifluoromethyl)-phenyl]furo[3,2-c]pyridine. Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 825–831, June, 2006.     

离子液体中顺式-1,2,3-三(2-呋喃基)-2-丙烯-1-酮的合成

以离子液体[bmim][BF4]为反应溶剂,糠偶酰与2-呋喃基亚甲基叶立德经Wittig缩合合成了新化合物--顺式-1,2,3-三(2-呋喃基)-2-丙烯-1-酮,产率90%,其结构经1H NMR和MS表征.     

Interaction of (z)-4-bromo-1,3-di(2-thienyl)- 2-buten-1-one with amines,synthesis of di(2-thienyl)azolo[<Emphasis Type="Italic">a</Emphasis>]pyridines

(Z)-4-Bromo-1,3-di(2-thienyl)-2-buten-1-one was obtained by the bromination of 1,3-di(2-thienyl)-2-buten-1-one by NBS in anhydrous CCl₄. The starting butanone was obtained by the condensation of 1-(2-thienyl)-1-ethanone by the action of SOCl₂. The reaction of (Z)-4-bromo-1,3-di(2-thienyl)-2-buten-1-one with tertiary amines such as Et₃N, pyridine, 1-alkyl-1,3-diazole, 1-alkylbenzimidazole, and 1-alkyl-1,2,4-triazole leads to quaternary salts. The azolium salts cyclize by the action of base to give di(2-thienyl)azolo[a]pyridinium derivatives. 3-Methyl-6,8-di(2-thienyl)[1,3]thiazolo[3,2-a]pyridin-4-ium and 2,4-di(2-thienyl)pyrido[2,1-b]benzothiazol-10-ium bromides were obtained by the same procedure but without separating the intermediate quaternary salts.     

Reaction of benzothiazol-2-one with 4-hydroxy-4-methyl-2-pentynonitrile

Reaction between the title compounds gave the unexpected 3-[5,5-dimethyl-2,5-dihydrofur-4-yl-2-(3-isopropanol-2-propenonitrile)imino]benzothiazol-2-one, as a result of the addition of two cyanoacetylene molecules.Irkutsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Irkutsk 664033. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 4, pp. 1003–1005, April, 1992.     

Syntheses of 4-(benzo[b]furan-2 or 3-yl)- and 4-(benzo[b]-thiophen-3-yl)piperidines with 5-HT2 antagonist activity

The syntheses of 4-(benzo[b]furan-3-yl)piperidines, 4-(benzo[b]furan-2-yl)piperidines and 4-(benzo[b]thiophen-3-yl)piperidines with 5-HT₂ antagonist activity are described. Reaction of 1-acetyl-4-(2,4-difluorobenzo-yl)piperidine 2 with methyl glycolate gave methyl 6-fluoro-3-(1-acetylpiperidin-4-yl)benzo[b]furan-2-carboxylate 3 , which was converted to 2-[2-[4-(benzo[b]furan-3-yi)piperidin-1-yl]ethyl-5,6,7,8-tetrahydro-1,2,4-triazolo-[4,3-a]pyridin-3(2H)-one hydrochloride 9 . Analogous benzo[b]furans 17a-d and benzo[b]thiophenes 10a,b and 18a were prepared by a similar method. Cyclization of 4-fluoro-2-(4-pyridinylmethoxy)acetophenones 20a,b afforded 4-(benzo[b]furan-2-yl)pyridines 21a,b , which were converted to 2-[2-[4-(benzo[b]furan-2-yl)-piperidin-1-yl]ethyl-5,6,7,8-tetrahydro-1,2,4-triazolo[4,3-a]pyridin-3(2H)-one hydrochlorides 24a,b. Among them, benzo[b]furans 9 and 17a,d and benzo[b]thiophenes 10 and 18a showed potent 5-HT₂ antagonist activity in vitro.     

Synthesis and Crystal Structure of 3，3－Diphenylnaphtho ［1，2－b］furan－2（3H）－one

ＳｙｎｔｈｅｓｉｓａｎｄＣｒｙｓｔａｌＳｔｒｕｃｔｕｒｅｏｆ３，３－Ｄｉｐｈｅｎｙｌｎａｐｈｔｈｏ［１，２－ｂ］ｆｕｒａｎ－２（３Ｈ）－ｏｎｅＭｅｎｇＪｉ－Ｂｅｎ；ＷｅｎＺｈｏｎｇ；ＷａｎｇＹｏｎｇ－Ｍｅｉ；ＷａｎｇＲｕ－Ｊｉ；ＷａｎｇＨｏｎｇ－Ｇｅ...     

Synthesis and Photoisomerization of 3-Cyano-6,6-dimethyl-4-(4-nitrophenylvinyl)-5,6-dihydropyran-2-one

The condensation of 4-nitrobenzaldehyde with 3-cyano-4,6,6-trimethyl-5,6-dihydropyran-2-one leads to the formation of a crotonization product and a compound of the Michael adduct type. The main product of the photochemical conversion of (E)-3-cyano-6,6-dimethyl-4-(4-nitrophenylvinyl)-5,6-dihydropyran-2-one is the Z-isomer. Investigation of the photoisomerization of 3-cyano-6,6-dimethyl-4-(4-nitrophenylvinyl)-5,6-dihydropyran-2-one by the semiempirical AM1 method showed that in the ground state the E-isomer was thermodynamically more stable than the E-isomer. E-Z-photoisomerization is effected most probably through the lowest excited singlet state S₁.     

Efficient synthesis and resolution of novel 2-(hydroxymethyl)-7,8-dihydro-1H-indeno[5,4-b] furan-6(2H)-one by lipase Pseudomonas cepacia

Lipase Pseudomonas cepacia catalyzed acylation of (±)-2-(hydroxymethyl)-7,8-dihydro-1H-indeno[5,4-b] furan-6(2H)-one using vinyl acetate as the acyl donor in acetone gave (−)-(R)-2-acetoxy-2-(methyl)-7,8-dihydro-1H-indeno[5,4-b] furan-6(2H)-one and (+)-(S)-2-(hydroxymethyl)-7,8-dihydro-1H-indeno[5,4-b] furan-6(2H)-one with high enantiomeric excess. Enantiomerically pure 2-(hydroxymethyl)-7,8-dihydro-1H-indeno[5,4-b] furan-6(2H)-one are useful intermediates for the preparation of Ramelteon, an FDA approved drug for the treatment of insomnia.     

Syntheses of Heterocycles from the Sodium Salts of 3-(1-Adamantyl)-1-hydroxy-1-propen-3-one and 4-(1-Adamantyl)-1-hydroxy-1-buten-3-one

The interaction of the sodium salts of 3-(1-adamantyl)-1-hydroxy-1-propen-3-one and 4-(1-adamantyl)-1-hydroxy-1-buten-3-one with hydroxylamine, hydrazine, and guanidine leads to the synthesis of 5-(1-adamantyl)-5-hydroxy- and 5-(1-adamantylmethyl)-5-hydroxy-2-isoxazolines, 3-(1-adamantyl)- and 3-(1-adamantylmethyl)pyrazoles, 3-(1-adamantyl)-2-phenylpyrazole, and 4-(1-adamantyl)-2-amino- and 4-(1-adamantylmethyl)-2-aminopyrimidines.     

Synthesis of Geminally Activated 4-(Furan-2-yl)- and 4-(Thiophen-2-yl)-1-nitrobuta-1,3-dienes

The condensation of 3-(furan-2-yl)- and 3-(thiophen-2-yl)prop-2-enals with nitro-substituted CH acids, namely ethyl nitroacetate, nitroacetone, nitroacetophenone, and nitroacetonitrile, afforded a series of geminally activated nitro dienes, 4-(furan-2-yl)- and 4-(thiophen-2-yl)-1-nitrobuta-1,3-dienes. The product structure was confirmed by NMR and IR spectroscopy.

     

Condensed heterocycles. 42. Synthesis and some properties of 3-hydroselenobenzo[b]furan-2-carbaldehyde and 2-hydroselenobenzo[b]furan-3-carbaldehyde

The reactions of 3-chlorobenzo[b]furan-2-carbaldehyde and 2-bromobenzo[b]furan-3-carbaldehyde with sodium hydrogen selenide have yielded isomeric hydroseleno aldehydes which, under the action of atmospheric oxygen, have oxidized to diselenides, while alkylation of the seleno aldehydes with methyl iodide leads to the formation of the corresponding methylseleno derivatives.For communication 41, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1177–1179, September, 1984.     

Preparation and root growth-inhibitory activity of N-substituted 2-(2-chloroacetamido)-3-(furan-2-yl)propanamides

A series of N-substituted 2-(2-chloroacetamido)-3-(furan-2-yl)propanamides (16--18) was prepared through the reaction of chloroacetyl chloride with N-substituted 2-amino-3-(furan-2-yl)propanamides (15), which were obtained via condensation of 2-(tert-butoxycarbonylamido)-3-(furan-2-yl)propanoic acid (Boc-furylalanine) (8) with amines (9, 11, 13), followed by hydrolysis of the resultant N-substituted Boc-furylalanine acid amides (10, 12, 14) in the presence of HCl/dioxane. The biological activity of the prepared 16, 17 and 18 as root growth inhibitors was examined by germination assay using rape seed. At the concentration of 5.0 x10 (-5) M, the most active compound, 2-(2-chloroacetamido)-N-(2,6-diethylphenyl)-3-(furan-2-yl)propanamide (16 n), showed potent root growth-inhibitory activity of 76% towards rape seedlings.     

Synthesis and Antitumor Activity of New 5-Ylidene Derivatives of 3-(Furan-2-ylmethyl)-2-sulfanylidene-1,3-thiazolidin-4-one

Russian Journal of Organic Chemistry - Reactions of 3-(furan-2-ylmethyl)-2-sulfanyidene-1,3-thiazolidin-4-one with aromatic and heterocyclic aldehydes afforded a series of previously unknown...     

Synthesis and Reactivity of Fusion Product of 2-Methylthiazole Fragment to 2-(Furan-2-yl)benzimidazole

Reaction of 1,2-diamino-4-nitrobenzene with furan-2-carbaldehyde in the presence of copper sulfate afforded 2-(furan-2-yl)-5(6)-nitro-1H-benzimidazole. Its N-methylation provided 1-methyl-5(6)-nitro isomers. After reduction of isomers with tin in conc. HCl a pure 3-methyl-2-(furan-2-yl)benzimidazol-5-amine was obtained. The condensation of this amine with acetic anhydride led to the formation of N-[3-methyl-2-(furan-2-yl)benzimidazol-5-yl]acetamide whose treatment with excess P₂S₅ in anhydrous pyridine resulted in the corresponding thioamide. The latter was oxidized with K₃[Fe(CN)₆] in alkaline environment to obtain 2,8-dimethyl-7-(furan-2-yl)-8H-imidazo[4,5-g][1,3]benzothiazole. Its reactions of electrophilic substitution were studied: nitration, bromination, sulfonation, formylation, acylation. The substituent is introduced exclusively in the position 5 of the furan ring.     

Synthesis of 3-(2-Oxo-2,3-dihydrobenzo[<Emphasis Type="Italic">b</Emphasis>]furan-3-ylidenehydrazono)-2,3-dihydrobenzo[<Emphasis Type="Italic">b</Emphasis>]furan-2-one

Reactions of benzophenone and fluoren-9-one hydrazones with (2-hydroxyphenyl)oxoacetic acid gave [carboxy(2-hydroxyphenyl)methylidenehydrazono](2-hydroxyphenyl)acetic acid which underwent intramolecular cyclization with formation of 3-(2-oxo-2,3-dihydrobenzo[bfuran-3-ylidenehydrazono)-2,3-dihydrobenzo[b]furan-2-one. The symmetric azine was also obtained by reactions of (2-hydroxyphenyl)oxoacetic acid with triphenylphosphoranylidenehydrazones derived from benzophenones, fluoren-9-one, and 1-methyl-2,3-dihydro-1H-indole-2,3-dione.     

Novel,Simple, and Efficient Synthesis of 3-(2-(5-(Benzylideneamino)-3-phenyl-1H-pyrazol-1-yl)thiazol-4-yl)-4-hydroxy-6-methyl-2H-pyran-2-one Derivatives via a One-Pot,Four-Component Condensation Reaction

The synthesis of 3-(2-(5-(benzylideneamino)-3-phenyl-1H-pyrazol-1-yl)thiazol-4-yl)-4-hydroxy-6-methyl-2H-pyran-2-one derivatives was achieved through a one-pot, four-component reaction involving condensation of 3-(2-bromoacetyl)-4-hydroxy-6-methyl-2H-pyran-2-one, thiosemicarbazide, phenacylcyanaide, and various aryl aldehydes in dry alcohol and few drops of acetic acid under reflux condition. This four-component reaction has some advantages such as ease of handling, good yields, and easy workup. All structures of newly prepared compounds were confirmed by analytical and spectral data.     

A facile and practical preparation of 5,7-dihydroxy-3-(4-nitrophenyl)-4H-1-benzopyran-4-one

In spite of the fact that several preparative methods for the synthesis of hydroxylated isoflavones were reported during the past fifty years, none is suitable for the preparation of isoflavones containing 5,7-dihydroxyl functions. This paper reports a simple, large scale preparation of 5,7-dihydroxy-3-(4-nitrophenyl)-4H-1-benzopyran-4-one ( 2a ) by the condensation of the readily available 4-nitrobenzyl 2,4,6-trihydroxyphenyl ketone ( 1a ) and acetic-formic anhydride in high yields. Similar isoflavones, such as 7-hydroxy-3-(4-nitrophenyl)-4H-1-benzopyran-4-one ( 2b ) can also be obtained in good yields in analogous manner.     

Palladium acetate-catalyzed cyclization reaction of 2,3-allenoic acids in the presence of simple allenes: an efficient synthesis of 4-(1'-bromoalk-2'(Z)-en-2'-yl)furan-2(5H)-one derivatives and the synthetic application

We have realized a cyclization reaction of 2,3-allenoic acids 1 in the presence of simple alkyl- or aryl-substituted allenes 3. In this reaction, the cyclic oxypalladation of 2,3-allenoic acid with Pd(II) would afford the furanonyl palladium intermediate 2, which could be trapped by the simple allene to afford a pi-allylic intermediate anti-9. This intermediate anti-9 could be nucleophilically attacked by Br- to yield 4-(1'-bromoalk-2'(Z)-en-2'-yl)furan-2(5H)-one derivatives Z-5 and Pd(0). The in-situ formed Pd(0) was efficiently converted to the catalytically active Pd(II) species by benzoquinone in HOAc. The functional groups, such as malonate, acetoxyl, and phthalic amide in allene 3, are tolerable under the current conditions. High efficiency of chirality transfer was observed when optically active 2,3-allenoic acids were used, which reveals that the formation of the intermediates 2 was a highly stereoselective anti-oxypalladation process. The highly selective formation of Z-isomer may be explained by face-selective coordination of allene 3 with the palladium atom in intermediate 2: the palladium atom coordinates to the terminal C=C double bond of allene 3 from the face opposite to the substituent group to avoid the steric congestion. The products Z-5 could be further elaborated via the S(N)2 nucleophilic substitution with amine or sodium benzenesulfinate, the reduction of the C-Br bond by NaBH(4), and the CuBr.SMe(2)-catalyzed S(N)2'-substitution with CH(3)MgBr.     

Synthesis of 1,1,1 - trifluoro-2-penten-4-one

The 1,1,1-trifluoro-2-penten-4-one has been prepared from trifluoroacetaldehyde by two different ways. Its condensation with a cyclohexanone enamine leads, by annelation, to 4-trifluoromethyl-Δ-1,9 (and Δ-9,10)-octalin- 2-one.     

5-(1,3-Benzothiazol-2-yl)furan-2-carbaldehyde in the Design of Antitumor Agents

Russian Journal of Organic Chemistry - Reactions of 5-(1,3-benzothiazol-2-yl)furan-2-carbaldehyde with 2-acetylfuran, 2-acetylthiophene, and some compounds containing an active methylene group gave...