Regioselective synthesis of 2-trivinylsilyl-2Н,3Н-[1,3]thia- and -selenazolo[3,2-a]pyridin-4-ium chlorides

Russian Chemical Bulletin -     

The reaction of 4-aminocoumarin with β-carbonyl-substituted 4Н-chromenes: synthesis of 5H-chromeno[4,3-b]pyridin-5-one derivatives

Chemistry of Heterocyclic Compounds - Reactions of 4Н-chromene-3-carbaldehydes and 1Н-benzo[f]chromene-3-carbaldehydes with 4-aminocoumarin were used to obtain a series of...     

3-Amino-4-[5-(chloromethyl)-1,2,4-oxadiazol-3-yl]furazan –a multifunctional synthon for the synthesis of 1,2,5-oxadiazole derivatives

Chemistry of Heterocyclic Compounds - The chemical properties of 3-amino-4-[5-(chloromethyl)-1,2,4-oxadiazol-3-yl]furazan were scrutinized: acylation of the amino group and its oxidation to azo and...     

Intramolecular Ullmann-type C−N coupling for the synthesis of substituted benzo[4,5]imidazo[1,2-a]pyrrolo[3,4-c]pyridines

An efficient CuI catalyzed intramolecular Ullmann-type C−N coupling reaction is described here. Newly substituted 1H-benzo[4,5]imidazo[1,2-a]pyrrolo[3,4-c]pyridine-1,3,5(2H, 11H)-trione has been easily synthesized from ortho halogenated N-substituted pyrrolo[3,4-c]pyridine-1,3,6(5H)-triones in presence of CuI catalyst and K₂CO₃ base without any ligand. This procedure is based on intramolecular Ullmann-type reaction and provides a proficient method of making fused tetracyclic heterocycles.     

Synthesis and Structure of 2-(1Н-Indol-1-yl)-6-ferrocenyl-4-(2-chloroimidazo[1,2-a]pyridin-3-yl)pyrimidine

A 2,4,6-trisubstituted pyrimidine including a 2-(1H-indol-1-yl) substituent was synthesized by the reaction of 1-ferrocenyl-3-(2-chloroimidazo[1,2-a]pyridin-3-yl)propanone with 2,5-dimethoxytetrahydrofuran. The structure of the synthesized compound was confirmed by IR and ¹Н NMR spectroscopy, and X-ray diffraction analysis. It has been shown that the ferrocene-containing compounds synthesized in the present work all demonstrate intramolecular charge transfer which is evidenced by the observation of the corresponding absorption bands with λ ^abs_max > 480 nm. The oxidation potential of ferrocene (E ^Fc_ox ) in all the compounds is higher than 700 mV.

     

Novel One-Pot Multicomponent Synthesis of Substituted 2,3-Dihydro-2-(6-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-3-yl)phthalazine-1,4-diones and Substituted 3-[3-(N′-Benzylidene-hydrazino)-7H-[1,2,4] triazolo[3,4-b][1,3,4]thiadiazin-6-yl]-4-hydroxy-6-methyl-pyran-2-ones

A one-pot procedure has been developed for the synthesis of substituted 2,3-dihydro-2-(6-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-7H-[1,2,4]triazolo[3,4-b] [1,3,4]thiadiazin-3-yl)phthalazine-1,4-diones by reaction of 3-(2-bromoacetyl)-4-hydroxy-6-methyl-2H-pyran-2-one, 4-amino-5-hydrazino-4H-[1,2,4]triazole-3-thiol, and phthalic anhydrides in acetic acid medium. Similarly, a one-pot, three-component synthetic procedure has been developed for substituted 3-[3-(N¹-benzylidene-hydrazino)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-6-yl]-4-hydroxy-6-methyl-pyran-2-ones from 3-(2-bromoacetyl)-4-hydroxy-6-methyl-2H-pyran-2-one, 4-amino-5-hydrazino-4H-[1,2,4]triazole-3-thiol, and various aromatic aldehydes in absolute ethanol and a few drops of glacial acetic acid.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

Porphyrin-LEGO®: synthesis of a hexafullereno-diporphyrin using porphyrins programmed for [4+2]-cycloaddition

A hexafullereno-diporphyrinoid was obtained in a sequence of cycloaddition steps using porphyrins programmed for [4+2]-cycloaddition reactions and C(60)-fullerene.     

Synthesis of 2-(4′-Morpholin-4″-yl-5H-chromeno-[2,3-d]pyrimidin-2′-yl)phenol from salicylaldehyde and substituted acrylonitriles

The synthesis of 2-(4??-morpholin-4??-yl-5H-chromeno[2,3-d]pyrimidin-2??-yl)phenol was performed via the reaction of salicylaldehyde with the substituted acrylonitriles. Its structure was confirmed by the X-ray analysis.     

Electrooxidative [3 + 2] annulation of amidines with alkenes for the synthesis of spiroimidazolines

The electrooxidative [3 + 2] annulation of amidines with 2-arylideneindane-1,3-diones or 4-alkylidene pyrazolones is reported using NaI as a redox catalyst and electrolyte under constant current electrolysis in an undivided cell. The current strategy features excellent functional group tolerance, simple operation, and mild conditions, thus providing an environmentally benign and efficient access to spiroimidazolines in moderate to good yields.     

QSAR Study on Some N-[5-（2-Furanyl）-2-methyl- 4-oxo-4H-thieno[2,3-d]pyrimidin-3-yl]-carboxamide and 3-Substituted-5-（2-furanyl）-2-methyl-3H-thieno- [2,3-d]pyrimidin-4-ones Using Three-dimensional Holographic Vector of Atomic Interaction Field

Study on the quantitative structure-activity relationship （QSAR） of 26 compounds, N-[5-（2-furanyl）-2-methyl-4-oxo-4H-thieno[2,3-d]pyrimidin-3-yl]-carboxamide and 3-substituted- 5-（2-furanyl）-2-methyl-3H-thieno[2,3-d]pyrimidin-4-ones, with three-dimensional holographic vector of atomic interaction field （3D-HoVAIF） was carried out. SMR-PLS QSAR models have been created and good correlation coefficients and cross-validated correlation coefficients were obtained. The result shows that the models have good prediction capability and favorable stability and the 3D-HoVAIF is applicable to the molecular structural characterization and biological activity prediction.     

Gram-scale synthesis of anti-pancreatic flavonoids (±)-8-[1-(4′-hydroxy-3′-methoxyphenyl)prop-2-en-1-yl]-chrysin and -galangin

Gram-scale total synthesis of (±)-8-[1-(4′-hydroxy-3′-methoxyphenyl)prop-2-en-1-yl]-galangin (1) and -chrysin (2) has been accomplished in eight steps from commercially available phloroglucinol and three steps from commercially available chrysin, respectively, featuring an efficient introduction of C(8) (1-prop-2-en-1-yl)phenyl moiety in the natural products through chemo- and regioselective cinnamylation and regioselective aromatic Claisen rearrangement.     

The reaction of β-dicarbonyl compounds with trifluoromethyl-sulphenyl chloride Part II. The synthesis of 3-SCF3 substituted 2- and 4-quinolinones

3-SCF₃ substituted 4-methyl-2(1H)-, 4-phenyl-2(1H)-, 2-methyl-4(1H), and 2-phenyl-4(1H)-quinolinones were obtained by cyclization of the respective -SCF₃ submitted acetoacetanilides or benzoylacetanilides or their β-phenylimino analogues in concentrated sulphuric acid upon heating. The structures of the compounds obtained were elucidated by elemental analysis and their IR, ¹H and ¹⁹F NMR, and mass spectra.     

Synthesis of 2s, 4s, 5s -dihydroxypipecolic acid and bulgecinine [2s,4s,5r-4-hydroxy-5- (hydroxymethyl)proline] from d-glucuronolactone,a strategy for the synthesis of 2s,4s-4-hydroxy-α-amino acids

The efficient synthesis of 4S,5S-2-(N-benzyloxycarbonyl)amino-5,6-dihydroxyhex-2-en-4-olide (4) from D-glucuronolactone is described, the potential of (4) as a divergent intermediate for the synthesis of 2S,4S-4-hydroxy-α-amino acids is illustrated by the conversion of (4) to 2S,4S,5S-dihydroxypipecolic acid and bulgecinine [2S,4S,5R-4-Hydroxy-5-(hydroxymethyl)-proline].     

A [Pd]-mediated ω-alkynone cycloisomerization approach for the central tetrahydropyran unit and the synthesis of C(31)-C(48) fragment of aflastatin A

A concise assembly of the central tetrahydropyran unit of aflastatin A featuring a Pd-mediated alkynone cycloisomerization to provide a glycal and its subsequent stereoselective hydroboration to deliver the requisite stereochemistry at C(33) and C(34) centers is documented.     

Microwave-assisted,methanesulfonic acid-catalyzed synthesis of 3,3′-(arylmethylene)bis(4-hydroxy-2H-chromen-2-ones)

Efficient synthesis of 3,3′-(arylmethylene)bis(4-hydroxy-2H-chromen-2-ones) has been achieved by methanesulfonic acid-catalyzed, microwave-assisted reaction of 4-hydroxycoumarin and aromatic aldehydes in ethanol. The procedure has the advantages of high yield, short reaction time, low energy consumption, and convenient work-up. Compound structures were confirmed by IR, ¹H NMR, and ¹³C NMR spectroscopy and by elemental analysis.     

Synthesis of N,N′-bis[4-(1H-1,2,3-triazol-1-yl)furazan-3-yl]-methylenediamine derivatives

[3+2] Cycloaddition of azide groups of N,N′-bis(4-azidofurazan-3-yl)methylenediamine to 1,3-dicarbonyl compounds and malonodinitrile was shown to proceed regioselectively with the formation of the corresponding N,N′-bis[4-(1H-1,2,3-triazol-1-yl)furazan-3-yl]methylenediamine derivatives. The reactions of N,N′-bis(4-azidofurazan-3-yl)methylenediamine with cyanoacetic acid ethyl ester and amide led to the formation of the product of transformation of the azide group in the starting compound to the amino groups.     

Synthesis and Reactivity of 2-(Furan-2-yl)benzo[1,2-d:4,3-d′]bis[1,3]thiazole

Russian Journal of Organic Chemistry - Acylation of 1,3-benzothiazol-6-amine with furan-2-carbonyl chloride in propan-2-ol gave N-(1,3-benzothiazol-6-yl)furan-2-carboxamide which was converted to...     

N-acetylchloroacetamide in the synthesis of functionally-substituted pyrido[3′,2′∶4,5]-thieno[3,2-d]pyrimidin-4(3H)-ones

3-Cyano-2(1H)-pyridinethiones react with N-acetylchloroacetamide in ethanol in the presence of KOH to give pyrido[3,24,5]thieno[3,2-d]pyrimidin-4(3H)-ones.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 837–840, June, 1997.     

Studies on the Cyclisation of 4-[2′-Cyclohexenyl]-3-hydroxy[1]benzopyran-2-one

The bicyclic coumarin derivative-1, 3 propano-2-bromo-1,2-dihydro-3H-pyrano [2, 3-c] [1]benzo-pyran-5-one (8) was synthesised by a sequence of reaction viz. acetylation of 4-[2′-cyclohexenyl] -3-hydroxy [1] benzopyran-2-one (4), addition of bromine to cyclohexenyl double bond and treating the resulting acetyldi-bromo derivative (7) with 4% alcoholic KOH. Benzofuro [2, 3-c] [1] -benzopyran-6-one (10) was synthesised from 4 via oxymercuration with mercuric acetate in methanol followed by dehydrogenative damercuration with Pd-C in refluxing diphenyl ether.