Synthesis, Vasodilating, Antithrombotic and Cardioprotective Activity of Pyridyl Substituted 5-Silyl(Germyl)Isoxazolines-2

The reactions of [2+3] cycloaddition of pyridylnitrile oxides to vinyl- and allylgermanes proceed regioselectively and afford 5-Ge-substituted isoxazolines-2. We have synthesized 9 new pyridyl substituted 5-Si(Ge)-isoxazolines-2 and investigated their biological activity. The vasodilating, anticoagulant and cardioprotective activities of 5-Si(Ge) substituted isoxazolines-2 have been studied in vitro and in vivo. Substitution of the silicon atom for the germanium one leads to the significant increase in vasodilating, antithrombotic and cardioprotective activity. The insertion of the methylene group between Ge and the isoxazoline ring reduces the vasodilating activity. The most active isoxazoline - 3-(5‵-triethylgermyl-3‵-isoxazolinyl)pyridine hydrochloride protects the heart from rhythm disturbances and lethality during ischaemia-reperfusion

Synthesis and Biological Activity of Silyl- and Germylsubstituted Trifluroacetylfurans

A series of silyl, germyl and alkyl substituted trifluoroacetylfurans has been synthesized under Friedel-Crafts electrophilic acylation conditions. Biological investigations have demonstrated that germyl derivatives of trifluoroacetylfuran are more toxic than the silicon analogues. 5-Triethylgermyl-2-trifluoroacetylfuran was the most toxic compound (LD50, 11.2 mg kg-1, i.p. for white mice), 200 times more toxic than the silicon analogue. 5-t-Butyl- and 5-trimethylsilyl-2-trifluroacetylfuran prolong the duration of ethanol anaesthesia by 220 and 140%. 5-Triethylgermyl-2-trifluroacetylfuran exibited high anesthetic activity in hexobarbital test (prolonged the duration by 137%). Some of compounds influenced muscle tone and locomotor coordination parameters. 5-Triethylgermyl-2-trifluomacetylfuran exibited analgesic activity (ED50, 0.9 mg kg-1)

Synthesis of Silicon and Germanium Containing Heteroaromatic Sulfides as Cholesterol Level Lowering and Vasodilating Agents

Silicon and germanium containing heteroaromatic sulfides have been prepared using phase transfer catalytic (PTC) system thiol / Si or Ge containing alkyl halide / solid KOH / 18- crown-6 / toluene. The target sulfides were isolated in yields up to 92 %. It has been found that 2-{[dimethyl (β-triethylgermylethyl)-silylmethyl]thio}-1-methylimidazole and 2-{[dimethyl(β-triphenylsilylethyl) silyl-methyl]thio}benzothiazole are the most active cholesterol level lowering and vasodilating agents

Synthesis and Cytotoxicity of Silicon and Germanium Containing Pyridine Oxime O-Ethers

Silicon and germanium containing pyridine aldoxime, ketoxime and amidoxime O-ethers have been prepared using phase transfer catalytic systems oxime alkyl halide solid KOH 18-crown-6 benzene and oxime alkyl halide solid K2CO3 or Cs2CO3 18-crown-6 toluene. Cytotoxic activity of silicon and germanium containing pyridine oxime O-ethers was tested in vitro on two monolayer tumor cell lines: MG- 22A (mouse hepatoma) and HT-1080 (human fibrosarcoma). O-[3-Yriethylsilylpropyl]- and O-[3-(1-methyl- 1-silacyclopentyl)propyl] oximes of pyridine aldehydes and ketones exhibit high cytotoxicity. Presence of methyl group in the pyridine ring considerably decreased activity of amidoxime O-ethers. Oxime ethers containing two elements are essentially inactive. For 2-acetylpyridine oxime ethers the activity increases in order of alkyl substituents: Et3GeCH2CH2SiMe2CH2 < Et3SiCH2CH2CH2 < (CH2)4SiCH2CH2CH2. Cytotoxicity of ketoxime O-ethers is considerably lower in comparison with aldoxime O-ethers

Cytotoxic Activity of Silyl- and Germyl-Substituted 4,4-Dioxo-3a,6a-Dihydrothieno[2,3−d]isoxazolines-2

The [2+3] dipolar cycloaddition of nitrile oxides to the double C = C bonds of thiophene-1, 1-dioxides leads to formation of the fused isoxazolines-2 (1, 2). Tumor growth inhibition of these compounds strongly depends on the nature of group IV A element increasing from slightly active tert-butyl derivatives to silicon and germanium containing analogues. The products of benzonitrile oxide cycloaddition have greater cytotoxic effect than the compounds obtained from the cycloaddition reaction of 2, 5-disubstituted thiophene-1, 1-dioxides with acetonitrile oxide. Fused silyl substituted isoxazolines-2 are stronger NO-inducers than their germyl and tert-butyl analogues

(E)-2-(4-Benz­yloxy-2-hy­droxy­benzyl­idene)-N-phenyl­hydrazinecarbothio­amide

The title compound, C21H19N3O2S, exists in the thione form. The configuration about the C=N bond is E. The hydrazinecarbothio­amide unit adopts an almost planar arrangement, with maximum deviations of 0.016 (3) and −0.016 (2) Å for the two thio­urea N atoms. An intra­molecular O—H⋯N hydrogen bond occurs. Weak inter­molecular N—H⋯S, C—H⋯O and C—H⋯π inter­actions are observed in the crystal structure

Ethyl 1-tert-butyl-2-(4-methoxy­phen­yl)-1H-benzimidazole-5-carboxyl­ate

In the title mol­ecule, C21H24N2O3, the imidazole ring is essentially planar, with a maxium deviation of 0.015 (1) Å. The dihedral angle between the benzene and imidazole rings is 65.47 (6)°. The crystal packing is stabilized by weak inter­molecular C—H⋯O and C—H⋯N hydrogen bonds, forming zigzag chains along the c axis. The crystal structure is further stabilized by C—H⋯π inter­actions

Silacyclic Derivatives of Heteroaromatic Sulfides as Selective Cholesterol Level Lowering and Vasodilating Agents

Silacyclic derivatives of heteroaromatic sulfides have been prepared by using phase transfer catalytic (PTC) system thiol / silacyclopropyl iodide / solid K2CO3 / 18-crown-6 / toluene. The target sulfides were isolated in yields up to 70 %. The S-derivatives of N-methylimidazolyl, benzoxazolyl and 1,3,4-triazolyl thiols selectively lowered the low density lipoprotein (LDL) level in mice with the high cholesterol diet in nutrition

catena-Poly[[cadmium-bis­(μ-triethyl­ene­tetra­mine-κ4 N,N′:N′′,N′′′)-cadmium-(μ-triethyl­ene­tetra­mine-κ4 N,N′:N′′,N′′′)] hexa­fluoridogermanate]

The title fluoridogermanate, {[Cd2(C6H18N4)3][GeF6]}n, was synthesized hydro­thermally. The crystal structure comprises undulated cationic [Cd2(TETA)3]4+ chains (TETA is triethyl­ene­tetra­mine) propagating parallel to [101]. The central CdII atom is six-coordinated in a CdN6 set by three TETA ligands. The isolated [GeF6]2− units, serving as counter-anions, occupy the inter-chain spaces and simultaneously link adjacent chains into a three-dimensional network through extensive N—H⋯F hydrogen-bonding inter­actions. One of the ethyl­ene bridges of one TETA ligand is disordered around a twofold rotation axis