Synthesis of the precursors of bis(trichloro-1,4-benzoquinonyl)tetrathiafulvalenes

In reaction with potassium butylxanthate and sodium tert-butyltrithionate, 2,5-dihydroxy-3,4,6,7-tetrachloro-2,3-dihydrobenzo[b]furan forms the products from nucleophilic substitution of a chlorine atom, i.e., O-butyl S-(2,5-dihydroxy-4,6,7-trichloro-2,3-dihydrobenzo[b]furan-3-yl) xanthate and S-tert-butyl S-(2,5-dihydroxy-4,6,7-trichloro-2,3-dihydrobenzo[b]furan-3-yl) trithiocarbonate respectively. Recyclization of the xanthate in concentrated sulfuric acid gave 4-(2,5-dihydroxy-3,4,6-trichlorophenyl)-1,3-dithiol-2-one, which was oxidized by iron trichloride to the corresponding benzoquinone. Cyclization of the trithiocarbonate in the presence of trifluoroacetic and p-toluenesulfonic acid led to 7-hydroxy-5,6,8-trichloro-3a,8b-dithiolo[4,5-b]benzo[d]furan-2-thione.Dedicated to Prof. A. Katritzky in honor of his seventieth birthday.Riga Technical University, Riga LV-1048, Latvia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1055–1060, August, 1998.     

Synthesis,Crystal Structure and Antibacterial Activities of 4-Methyl-2-(4-methylphenyl)-5-(2-thiazolinyl)-1,3-thiazole

4-Methyl-2-(4-methylphenyl)-5-(2-thiazolinyl)-1,3-thiazole, a novel compound, was synthesized by the annulation of 5-hydroxyethylcarbamoyl-4-methyl-2-(4- methylphenyl)-1,3-thiazole with P_2S_5. 5-Hydroxyethylcarbamoyl-4-methyl-2-(4-methylphenyl)-1,3-thiazole was prepared from the starting material of p-tolunitrile. The newly synthesized compounds were characterized by elemental analysis, IR, NMR(~1H, ~(13)C) and MS spectra. Hence, the crystal of the title compound was obtained, and its structure was determined by X-ray diffraction analysis. The crystal belongs to the triclinic system, space group P1 with a = 7.354(4), b = 8.383(4), c = 11.543(6) ?, α = 76.688(6), β = 72.299(6), γ = 88.157(6)°, V = 659.2(6) ?~3, Z = 2, M_r = 274.39, D_c = 1.382 g/cm~3, μ = 0.386 mm~(-1), F(000) = 288, R = 0.0586 and w R = 0.1808 for 2984 unique reflections with 2213 observed ones(I 2σ(I)). The title compound was also screened for its antibacterial activities against Bacillus subtilis and Escherichia coli. The result indicates that the target compound presents potential antimicrobial activities, and that the minimum inhibitory concentration(MIC) values of the title compound against the two tested strains are both 62.5 μg/mL.     

Synthesis and molecular structure of 3-[5-(quinolin-2-yl)penta-1,4-dien-1-yl]-1,4-benzodioxin-2-one

Acid-catalyzed reaction of 6,10a-dihydroxy-3,4a,7,9-tetra(tert-butyl)-1,2,4a,10a-tetrahydrodibenzo-[b,e][1,4]dioxine-1,2-dione with 4-chloro-2,7,8-trimethylquinoline gave previously unknown 3,6,8-tri-tert-butyl-3-[2-tert-butyl-5-(4-chloro-7,8-dimethylquinolin-2-yl)-4-hydroxy-3-oxopenta-1,4-dien-1-yl]-5-hydroxy-1,4-benzodioxin-2-one whose structure was determined by X-ray analysis. The energy and structure parameters of possible isomers of the product in the gas phase and in solution were estimated by PBE0/6-31G** quantum-chemical calculations.     

多齿配体2,5-二羟基-1,4-苯醌缩氨基脲 (C_6H_4O_3NNHCONH_2.CHON(CH3_)_2)的合成及晶体结构

报道了含1个溶剂DMF的多齿配体2,5-二羟基-1,4-苯醌缩氨基脲的合成和晶体结构。该化合物(C10N4O5H14)属正交晶系,其空间群为P212121 a=13.221(6),b=17.709(5),c=5.347(4)?, V=1252.0(1)3,Z=4,F(000)=568, Dx=1.434g/cm3,Mr=270.25, m (MoKα)= 1.16 cm-1, 结构由直接法解出,全矩阵最小二乘法修正,最终的偏离因子R=0.0319,wR=0.0748。结构测定表明溶剂DMF分子和2,5-二羟基-1,4苯醌缩氨基脲间形成很强的氢键,后者可看作是两条共轭链的偶合物。     

Synthesis of new 1,3-thiazole derivatives from 2(5)-hydroxyalkyl-1,3-thiazole-5(2)-carbaldehydes

Reactions of substituted 2-hydroxyalkyl-1,3-thiazole-5-carbaldehydes and 5-hydroxyalkyl-1,3-thiazole-2-carbaldehydes with phenylhydrazine, isoniazid, N-substituted rhodanines were performed as well as Biginelli reaction with acetoacetic ester and urea. As a result, new 1,3-thiazole derivatives were obtained. They are of interest as potential bioactive substances.     

S-alkylthiosemicarbazonium salts in the synthesis of 1,2,4-triazolines. Molecular structure of 1,4-diacetyl-3-(5-nitrofurfurylthio)-5-(2-furyl)-δ2-1,2,4-triazoline

Acylation of S-alkylthiosemicarbazonium salts with acetic anhydride leads to the formation of 1,4-diacetyl-²-1,2,4-triazolines. It was also demonstrated, based on x-ray structural analysis, that the triazoline ring in the molecular structure of 1,4-diacetyl-3-(5-nitrofurfurylthio)-5-(2-furyl)-²-1,2,4-triazoline exists in an envelope or bent conformation.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 931–937, July, 1990.     

Synthese von (Methylthio)penam-Derivaten durch Keten-Addition an 4,5-Dihydro-5-(methylthio)-1,3-thiazole

Synthesis of (Methylthio)penam Derivatives via Keten Addition onto 4,5-Dihydro-5-(methylthio)-1,3-thiazoles The 4,5-dihydro-5-(methylthio)-2-phenyl-1,3-thiazoles 3a and 3b , easily prepared from the corresponding 1,3-thiazol-5(4H)-thiones and MeLi, react with dichloroacetyl chloride ( 5a ) and acidoacetyl chloride ( 5b ) in the presence of Et₃N to give (methylthio)penam derivatives 6 (Table 1). The reaction mechanism is either a [2 + 2] cycloaddition of in situ generated ketene or a two-step reaction (Scheme 2). The structure of 6f has been confirmed by X-ray crystallography (Fig. 2). The relative configuration of 6a-e follow from comparison of their ¹H-NMR spectra with those of 6f (Fig. 1). The 6-azidopenams 6d and 6f have been reduced to aminopenams 8a and 8b , respectively. Acylation of 8a with phenacetyl chloride yields 9 (Scheme 4).     

Co(III) complex with (E)-2-(2-(pyridine-2-ylmethylene)hydrazinyl)-4-(4-tolyl)-1,3-thiazole: structure and activity against 2-D and 3-D cancer cell models

Co(III) complex with a 2-hydrazonylthiazole ligand was synthesized and characterized by single-crystal X-ray diffraction. In the inner sphere of the complex, two monoionic ligands are coordinated tridentately forming octahedral geometry around Co(III). Activity of the complex was investigated on MCF-7 breast cancer cell line, with cisplatin (CDDP) as a reference compound. Results showed that after 24-h incubation, Co(III) complex revealed stronger cytotoxic activity compared to CDDP. Treatment of MCF-7 3-D cell model with the complex at 10 μM concentration achieved complete suppression of spheroid growth in almost the same extent as at 100 μM. In combination treatments on MCF-7 spheroids, the complex acted synergistically with CDDP, while additive interaction type was achieved when the complex was applied together with paclitaxel.     

Studies on the interaction of Eu(III) with lawsone (2-hydroxy-1,4-naphthoquinone), lapachol (2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthoquinone), juglone (5-hydroxy-1,4-naphthoquinone) and plumbagin (2-methyl-5-hydroxy-1,4-naphthoquinone)

pH-metric studies show that one mole of Eu(III) interacts with three molecules of each of juglone, plumbagin, lawsone and lapachol in solution. The stability and thermodynamics of these systems (50% aqueous acetone, 0.1 M KNO₃ ionic strength) are discussed and explained.     

Synthesis and structure of 2-(nitromethylene)-2H-1,4-benzothiazin-3(4H)-one

A new representative of benzothiazines, (2Z)-2-(nitromethylene)-2H-1,4-benzothiazin-3(4H)-one, was synthesized, and its structure was studied. According to ¹H NMR, IR, and UV spectral and X-ray diffraction data, the molecules are planar highly conjugated structures that exist in crystal as centrosymmetric dimers; the latter form layers overlapping with each other and held together by strong π-π interaction between the carbonyl groups of neighboring layers.     

4-Aryl-5-(pyrimidin-2′-yl)-1,4-dihydropyridines,-1,4-di- and -1,2,3,4-tetrahydropyrimidines

2-Acetonylpyrimidines readily undergo the Hantzsch—Biginelli cyclocondensation. This method was used to obtain derivatives of 1,4-dihydropyridine and 1,4-di- and 1,2,3,4-tetrahydropyrirrzidines, containing the pyrimidine fragment in the 5 position of the heterocycle.Institute of Bioorganic Chemistry and Petroleum Chemistry, Ukrainian Academy of Sciences, Kiev 253660. Translated from Khimiya Geterotsiklcheskikh Soedinenii, No. 5, pp. 679–685, May, 1994. Original article submitted January 20, 1994.     

Synthesis of 1,4-Bis(Chloromethyl)-2-Methoxy-5-Phenoxy Benzene

Much attention has been paid to Poly(p-Phenylene Vinylene) (PPV) because they are associated with good electro-optical characterization, especially electro-luminescence which first discovered by Burroughes in 1990^[1]. 1,4-bis(chloromethyl) benzene is an important tool to synthesize PPV by dehydrochlorination. So the chloromethylation of substituted benzene becomes active. We once synthesized a series of dialkoxyl bischloromethyl benzene^[2]. Unfortunately, short chain alkoxyl-substituted PPV has poor solubility, which limits its utility. There are little reports on aryloxy PPV up to now, while aryloxy-substituted PPV may has good mechanical properties.     

Heterocyclization of 2-(Propargylsulfanyl)-1,3-thiazole Derivatives by the Action of Halogens

Reactions of 2-(propargylsulfanyl)-5-methyl-1,3,4-thiadiazole, N-[5-(propargylsulfanyl)-1,3,4-thiadiazol- 2-yl]benzamide, 2-(propargylsulfanyl)-1,3-benzothiazole, and 2-(propargylsulfanyl)-4,5-dihydro-1,3- thiazole with iodine involved annulation of the unsaturated substituent with formation of fused thiazole ring. 2(5)-(Propargylsulfanyl)-1,3,4-thiadiazole derivatives reacted with bromine to give mixtures of heterocyclization products and bromine adducts to the triple bond. The bromination of 2-(propargylsulfanyl)-4,5-dihydro- 1,3-thiazole afforded only the bromine addition product to the triple bond.