Synthesis and Characterization of New Thiazolidin-4-one Derivatives

The synthesis of some new functionalized thiazolidin-4-one derivatives has been described. The N-substituted-thiosemicarbazides 3a-3i were obtained though the reaction of alkylamines 2a–2i , carbon disulfide, and hydrazine hydrate. The condensation reaction between 3a–3i and 4-amino-2-methanesulfanylpyrimidine-5-carboxaldehyde 1 afforded the thiosemicarbazones 4a–4i . The corresponding thiazolidin-4-ones 5a–5i were prepared by cyclization of 4a–4i with ethyl bromoacetate. The structures of the final products were confirmed by IR, ¹ H NMR, ¹³ C NMR, and HRMS.     

Straightforward synthesis of amino-3-hydroxypyridin-4-one iron chelators via BBr3-mediated tandem reduction of azides and deprotection of methyl ether

A novel and straightforward BBr₃-mediated tandem reduction of organic azide and demethylation of methyl ether were described. This method provides a new approach to prepare a series of new amino-3-hydroxypyridin-4-one iron chelators, which can be used in the treatment of iron also applicable to other substrates like benzyl azides and aryl azides.     

Synthesis and Vasodilatory Activities of New Pyrazolo[3,4—d] pyrimidin—4—one Derivatives

A series of pyrazole[3,4-d] pyrimidin-4-one derivatives were synthesized and tested for vasodilatory activities. All of them were new compounds and their structures were confirmed by IR,^1H NMR,MS and elemental analysis.     

Dehydration of 4-hydroxy-4-methyl-3-phenylamino-oxazolidin-2-ones

The dehydration of two 5,5-disubstituted 4-hydroxy-4-methyl-3-phenylaminooxazolidin-2-ones into the corresponding 4-methylene-3-phenylaminooxazolidin-2-ones has been carried out. The structure of the products was confirmed by X-ray diffraction analysis.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1512–1517, October, 2004.     

Synthesis and reactivity of 3-aralkoxy-4-imino-imidazolidin-2-ones: a novel class of 4-iminohydantoins

Reactions of diethylphosphonoalkyl α-aminonitriles with 1,1′-carbonyl-diimidazole or 1,1′-carbonyl-di-(1,2,4-triazole) and O-substituted hydroxylamines under acidic conditions gave 3-alkoxy-4-imino-imidazolidin-2-ones, whereas in presence of triethylamine 4-alkoxy(aralkoxy)imino-imidazolidin-2-ones were formed.     

Reactions of 3-hydroxy-1,2-dihydroquinazolin-4-ones with acid chlorides

The reactions of 3-hydroxy-1,2-dihydroquinazolin-4-ones with acid chlorides can afford compounds of different types. The structures of the products depend on the type of acid chloride used and on the nature of the substituent at position 2 of the 3-hydroxy-1,2-dihydroquinazolin-4-one. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1346–1349, July, 1999.     

Molecular Iodine: An Efficient and Environment Friendly Catalyst for the Synthesis of 3,5-Bis-(arylmethylidene)-tetrahydropyran-4-ones

A rapid, efficient, convenient and cost-effective procedure has been developed for the synthesis of 3,5-bis-(arylmethylidene)-tetrahydropyran-4-ones by the condensation of tetrahydropyran-4-one with araldehydes in the presence of catalytic amount of iodine to obtain the products in good to excellent yield. The reactions work at 25 °C and go to completion within 30–60 min.     

One-Pot Synthesis of 4-Hydroxy-3-phenyl-2H-pyrano[3,2-b]benzofuran-2-one Derivatives

Novel 4-hydroxy-3-phenyl-2H-pyrano[3,2-b]benzofuran-2-ones (15a–d), were synthesized in a one-step procedure by the reaction of substituted benzofuran-3-ones 12a–d and (chlorocarbonyl)phenyl ketene.     

Synthesis of 5-substituted 4-aminoalkylpyrazol-3-ones (isoxazol-3-ones) from 3-acyllactams

Structurally various 3-acyllactams act as 1,3-bielectrophiles in heterocyclization reactions with a variety of hydrazines and hydroxylamines to give aminoalkylpyrazolones and -isoxazol-ones in high yields.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 215–220, January, 2005.     

新型4,4-二甲基异噁唑-3-酮衍生物的合成及生物活性研究

以Baylis-Hillman加成物为起始原料,设计并合成了5个结构新颖的4,4-二甲基异唑-3-酮衍生物。所合成的化合物经IR、1HNMR和元素分析确证。生物活性测试结果表明,所合成的目标产物在2000gai/ha的剂量下均具有较好的除草活性。中间体1-(2,4-二氯苯基)-2-溴甲基丙烯酸乙酯具有杀虫活性,在600gai/ha的剂量下对朱砂叶螨防效为100%。     

1,2-Dihydro-2-thioxo-4H-3,1-benzothiazin-4-one: formation from carbon disulfide and isatoic anhydride

The reaction of isatoic anhydride (1) with carbon disulfide at room temperature unexpectedly afforded 1,2-dihydro-2-thioxo-4H-3,1-benzothiazin-4-one (2). The use of ¹³C-labeled carbon disulfide elucidated that CS₂ was entirely incorporated into the product.     

Separation of enantiomers and diastereomers of 4-hydroxy-2H-1,4-benzoxazin-3(4H)-one derivatives by capillary electrophoresis

Summary A high performance capillary electrophoresis (HPCE) procedure for the enantioseparation of the methyl acetals3 and4 of the natural products DIBOA1 and DIMBOA2, respectively, has been developed using borate buffers (pH 9–10 range), cyclodextrins as chiral additives and addition of up to 20% methanol. A mixture of GDIBOA5 and GDIMBOA6 of natural origin was also clearly separated. HPCE proved to be superior to HPLC by the first separation of GDIBOA5 and three of its diastereomers resulting from a synthetic approach to this acetalglucoside.     

Facile synthesis of 2-carboxanilido-3-arylquinazolin-4-ones from N1-(2-carboxyphenyl)-N2-(aryl)oxalamides

A simple and efficient approach for the synthesis of novel 2-carboxanilido-3-arylquinazolin-4-ones via the one-pot condensation of readily available N¹-(2-carboxyphenyl)-N²-(aryl)oxalamides with various aromatic amines is described. Notably, this methodology allows us to synthesize 3-aryl-quinazolin-4-ones using aromatic amines with various substituents, both electron-donating and electron-withdrawing, which ensures structural diversity of the products and an atomic-economic process.     

Synthesis and in vitro cytotoxic evaluation of 2-hydrazinylpyrido[2,3-b]pyrazin-3(4H)-one derivatives

A series of novel 2-hydrazinylpyrido[2,3-b]pyrazin-3（4H）-one derivatives were synthesized and evaluated for their cytotoxic activities against A549,MDA-MB-231 and HT-29 cell lines in vitro.Pharmacological data indicated that compounds 5b,5c,10a and 10g possessed marked cytotoxicity,especially 10a(with IC₅₀ values of 0.81,2.56 and 1.63μmol/L against A549,MDA-MB- 23 1 and HT29 cell lines,respectively),which had emerged as a lead compound.     

Synthesis of Arylidene Derivatives of 1-Aryl-3H-pyrrol-2-ones

The aminolysis of 5-aryl-3-arylidene-3H-furan-2-ones by the action of aromatic amines leads to the formation of substituted amides of 4-oxo acids, the subsequent azacyclization of which in the presence of acetic anhydride leads to the formation of 1,5-diaryl-substituted 3-arylidene-3H-pyrrol-2-ones. The mechanism of the occurring and alternative transformations is discussed.     

The Oxidation and Reduction of 4-Formyl-and 4-Acetyl-3-Arylsydnones

A convenient method to prepare methyl 3-arylsydnonylacetate (I) from 4-acetyl-3-arylsydnone with thallium (III) nitrate by oxidative rearrangement was investigated. 4-Formyl-3-arylsydnones were reduced by sodium borohydride at room temperature to produce 4-hydroxymethyl-3-arylsydnones (II) in moderate yields (65%-85%), but the corresponding 3-aryl-4-sydnonecarboxaldehyde arylhydrazone (III) was obtained by the electrolytic reduction.     

Thermal rearrangement of condensed alkoxy-substituted 2-trifluoromethyl-4H-pyran-4-ones to spiroannelated 3(2H)-furanones

Isomerization of the acetates and benzoates of condensed hydroxy-substituted 2-trifluoromethyl-4H-pyran-4-ones at 300–320°C gave the corresponding derivatives of spiroannelated 3(2H)-furanones. Their structure was confirmed by spectral data and by X-ray crystallographic analysis.Belarus State University, Minsk; Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1028–1034, August, 2000.     

Atom-Economic Route to Densely Functionalized Thiophenes via Base-Catalyzed Rearrangement of 5-Propargyl-2H-thiopyran-4(3H)-ones

An atom-economic route to densely functionalized thiophenes has been developed via base-catalyzed rearrangement of 5-propargyl-2H-thiopyran-4(3H)-ones involving tandem retro-thio Michael addition, propargyl isomerization, and intramolecular thio-addition to allenes.     

Oxidative Addition of N-Aminophthalimide and 3-Amino-2-methylquinazolin-4(3H)-one to Conjugated Azocyclopentenes and Azocyclohexenes

The oxidation of N-aminophthalimide and 3-amino-2-methylquinazolin-4(3H)-one in the presence of conjugated azocyclopentenes, azocyclohexenes, and 3-arylazocyclohexen-2-ones gives adducts at the carbon-carbon double bond corresponding to C-azoaziridines and/or bicyclic 2H-1,2,3-triazoles.