Bioactive Heterocycles Research Articles

Synthesis and Crystal Structure of 2-(4-Methoxyphenyl)-3-(3,4,5-trimethoxyphenyl)acrylonitrile

A new dipolarophile, used to construct bioactive heterocycles, 2-(4-methoxyphenyl)-3-(3,4,5-trimethoxyphenyl)-acrylonitrile, C19H19NO4, was synthesized by base-catalyzed reaction of 3,4,5-trimethoxybenzaldehyde with (4-methoxyphenyl)acetonitrile. The compound crystallizes in the monoclinic space group P21/c with cell parameters a = 7.2880(4)A, b = 8.1030(9)A, c = 28.460(3)A, β = 94.018(5)°, Z = 4. The structure exhibits both inter and intramolecular hydrogen bonds of the type C-H…O and C-H…N.

Graphical Abstracts

Graphical Section

Synthesis of Potentially Bioactive Heterocycles: Thermal [3,3]Sigmatropic Rearrangement of 4‐(4′‐Aryloxybut‐2′‐ynyloxy)‐6‐methyl‐2‐pyridone

Synthesis of a number of hitherto unreported 4‐aryloxymethylene‐7‐methyl‐2,3‐dihydropyrano[3,2‐c]pyridine‐5‐ones 4a–h have been achieved in moderate yields by the thermal [3,3]sigmatropic rearrangement of 4‐(4′‐aryloxybut‐2′‐ynyloxy)‐6‐methyl‐2‐pyridone.

Bioactive Heterocycles from Domino Wittig‐Pericyclic Reactions

AbstractFor Abstract see ChemInform Abstract in Full Text.

Bioactive Heterocycles from Domino Wittig-Pericyclic Reactions

Bioactive Heterocycles from Domino Wittig-Pericyclic Reactions

Synthesis of bioactive heterocycles: tandem reaction of 4- N-(4′-aryloxybut-2′-ynyl), N-methylaminocoumarin with 3-chloroperoxybenzoic acid

A number of 4- N-(4′-aryloxybut-2′-ynyl), N-methylaminocoumarins ( 4a– e ) on treatment with one equivalent of 3-chloroperoxybenzoic acid at 0–5°C for 10 min and then stirring at rt for 10 h afforded pyrrolo[3,2- c]coumarin derivatives in 70–75% yields. The 4- N-(4′-aryloxybut-2′-ynyl), N-methylaminocoumarins 4a– e were in turn prepared from 4-tosyloxycoumarin ( 2 ) and (4-aryloxybut-2-ynyl)- N-methylamine ( 3a– e ).

ChemInform Abstract: Synthesis of Bioactive Heterocycles: One‐Pot Regioselective Synthesis of Pyrano[3,2‐f]benzo[b]thiophene Derivatives.

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Synthesis of bioactive heterocycles: One pot regioselective synthesis of pyrano[3,2- f]benzo[ b]thiophene derivatives

Regioselective synthesis of hitherto unreported pyrano[3,2- f]benzo[ b]thiophene derivatives ( 8a-f) in 90–95% yields are reported by the application of a less studied rearrangement of 6-(4-aryloxybut-2-ynylthio)[1]benzopyran-2-ones ( 5a-f) via oxidation with m-chloroperoxybenzoic acid followed by thermal rearrangement and treatment with methanol. Substrates 5a-f are prepared by the reaction of 6-mercaptocoumarin (unstable) with 1-aryloxy-4-chlorobut-2-ynes ( 4) in refluxing acetone in the presence of anhydrous potassium carbonate and sodium iodide. 6-Mercaptocoumarin ( 3) is in turn prepared by the zinc-acid reduction of the disulfide ( 2) obtained by the reaction of the diazotised 6-aminocoumarin ( 1) with potassium ethylxanthate followed by decomposition. Pyrano[3,2- f]-benzo[ b]thiophene derivatives ( 8a-f) are easily converted to 1-acetylpyrano[3,2- f]benzo[ b]thiophene-7-one ( 12) when refluxed in acetic acid in the presence of catalytic amount of conc. sulfuric acid for 4 h.

Synthesis of curacin A, an antimitotic cyclopropane-thiazoline from the marine cyanobacterium Lyngbya majuscula

Charette asymmetric cyclopropanation, chiral thiazoline synthesis by thioamide cyclization under modified Mitsunobu conditions, Ti( iPrO) 4/bi-naphthol catalyzed allylstannane addition, and an exceptionally mild two-carbon homologation via dehydrative alkylation with phenylsulfonylacetonitrile/Ph 3P/ADDP convened in an efficient, stereocontrolled route to the title bioactive heterocycle.

The Nucleophilic Addition/Eiectrophilic Ring Closure Route to Bio-Active Heterocycles

Abstract: Many bio-active compounds contain one or more saturated or partially saturated heterocycles. Most of these contain one or more stereo­ centres. As a result any attempts to synthesize these compounds must take full account of the stereochemistry. In this article a new approach to the stereoselective synthesis of heterocycles is reviewed. The emphasis is on oxygen-containing heterocycles. The approach involves a sequence of a nucleophilic addition reaction followed by an electrophilic ring closure. Examples are given of the stereoselective synthesis of the heterocyclic subunits of macrolide and polyether antibiotics, y­butyrolactone autoregulators, marine polyether toxins and C-glycosides.

Reversed-phase retention characteristics of some bioactive heterocyclic compounds

The lipophilicities and specific hydrophobic surface areas of sixteen bioactive heterocyclic compounds were determined by reversed-phase thin-layer chromatography using various eluent systems. The data were evaluated by principal component analysis (PCA), separately calculated from the correlation and covariance matrices, and by cluster analysis. The ratio of the variances explained by the first PC component was high and was very similar for both PCA methods, suggesting that the eluents have common elution characteristics. The lipophilicities and specific hydrophobic surface areas of the compounds are well separated on the two-dimensional non-linear maps of PC variables, indicating the different information contents of the two physico-chemical parameters. The information contents of cluster analysis and two-dimensional non-linear mapping techniques were found to be similar but not identical.

ChemInform Abstract: Fluorine‐Containing Bioactive Heterocycles. Investigation of the Reactions of Fluorine‐Containing 3‐Hydrazino‐5H‐1,2,4‐triazino(5,6‐b)indoles with Carbon Disulfide and Synthesis of 2,3‐Dihydro‐1‐thioxo‐1,2,4‐triazolo(3,4‐c)‐1,2,4‐triazino(5,6‐b)indoles as Antibacterial Agents.

AbstractCyclocondensation reaction of the indole‐2,3‐diones (I) with thiosemicarbazide (II) gives the tricyclic compounds (III) which are converted to the hydrazino derivatives (V).

Fluorine containing Bioactive Heterocycles. Investigation of the Reactions of Fluorine containing 3-Hydrazino 5H-1 ,2,4-triazino[5,6-b]indoles with Carbon Disulphide and Synthesis of 2,3-Dihydro-1-thioxo-1 ,2,4-triazolo[3,4-c]-1 ,2,4- triazino[5,6-b] indoles as Antibacterial Agents

Fluorine containing Bioactive Heterocycles. Investigation of the Reactions of Fluorine containing 3-Hydrazino 5H-1 ,2,4-triazino[5,6-b]indoles with Carbon Disulphide and Synthesis of 2,3-Dihydro-1-thioxo-1 ,2,4-triazolo[3,4-c]-1 ,2,4- triazino[5,6-b] indoles as Antibacterial Agents

Fluorine containing Bioactive Heterocycles

Fluorine containing Bioactive Heterocycles

Fluorine containing bioactive heterocycles. PartII. Synthesis of some new fluorine containing arylglyoxals, their hydrates and 1,5‐disubstituted hydantoins

AbstractEight new fluorine containing arylglyoxals have been synthesized by the oxidation of the active methyl group of fluorinated acetophenones by selenium dioxide in dioxan‐water medium. The corresponding hydrates were obtained by dissolving arylglyoxals in minimum amounts of benzene and adding hot water. Seventeen new fluorine containing 1,5‐disubstituted hydantoins were subsequently prepared by the condensation of these arylglyoxals with arylureas in ethanol and characterized by ir, pmr and mass spectral studies. Representative compounds have been screened for their possible anticonvulsant and analgesic activities. None of the compounds show significant analgesic acitivity.

Fluorine Containing Bioactive Heterocycles. Part III: Synthesis of Some New Fluorine Containing Phenylglyoxals and 1,2,4-Triazine Derivatives

Fluorine Containing Bioactive Heterocycles. Part III: Synthesis of Some New Fluorine Containing Phenylglyoxals and 1,2,4-Triazine Derivatives

Bioactive Heterocyclic Compounds

Bioactive Heterocyclic Compounds