Synthesis, characterization and Cytotoxicity Evaluation of New Compounds from Oxazol-5(4H)-ones and Oxazoles Class Containing 4-(4-Bromophenylsulfonyl)phenyl Moiety

Steiger N-acylation of a-alanine with 4-(4-bromophenylsulfonyl)benzoyl chloride led to 2-[4-(4-bromophenylsulfonyl)benzamido]propanoic acid. This compound underwent intramolecular cyclization in the presence of N-methylmorpholine and ethyl chloroformate or acetic anhydride to the corresponding saturated azlactone. Then acylaminoacylation of dry aromatic hydrocarbons with 2-[4-(4-bromophenylsulfonyl)phenyl]-4-methyloxazol-5(4H)-one or 2-[4-(4-bromophenylsulfonyl) benzamido ]propanoyl chloride in the presence of anhydrous aluminum chloride led to corresponding a-acylamino ketones. These new intermediates were heterocyclized under the action of phosphorus oxychloride or concentrated sulfuric acid in the presence of acetic anhydride to the corresponding oxazoles. The newly synthesized compounds were characterized by spectral studies (FT-IR, UV-Vis, MS, 1H- and 13C-NMR) and elemental analysis. The purity of the new compounds was evaluated by RP-HPLC. The experimental research regarding to the in vitro cytotoxic activity of the new compounds were performed using Daphnia magna bioassay.

Study on Mullite Whiskers Preparation via Non-Hydrolytic Sol-Gel Process Combined with Molten Salt Method

Mullite whiskers were prepared via non-hydrolytic sol-gel process combined with molybdate molten salt using tetraethoxysilane and anhydrous aluminum chloride as precussor, anhydrous ether as oxygen donor, molybdate as molten salt. The effects of heat treatment temperature, molten salt amount, holding time on synthesis and morphology of mullite whiskers were investigated by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The results show that the mullite whiskers appeared at the lowest temperature of 800°C, and optimized mullite whiskers could be prepared at 900°C for 8 h with the mass ratio of xerogel and molybdate as 1:2, the diameter of the whiskers was in the range of 0.15-0.22 μm with the aspect ratio of more than 40.

Synthesis of New Pyrazoline - Phenoxathiin Derivatives

Phenoxathiin was prepared by the reaction of diphenyl ether with sulfur in the presence of anhydrous aluminum chloride. This work comprised the synthesis of new phenoxathiin derivatives containing heterocyclic moieties. These heterocyclic compounds were synthesized in three groups. The first group was made up of 2-(oxoalken-1-yl) phenoxathiin derivatives (3a-3j) obtained from the reaction of 2-acetylphenoxathiin with different aromatic aldehyde in the presence of sodium hydroxide. The other two groups involved compounds produced from the reaction of (3a-3j) with hydrazine hydrate in acetic acid to get 2-(1-acetyl pyrazolin-3-yl) phenoxathiin derivatives (4a-4j), and phenyl hydrazine in the presence of piperidine to afford 2-(1-phenyl pyrazolin-3-yl) phenoxathiin derivatives (5a-5j). All these compounds of two groups above were substituted in position (5) in pyrazoline ring with different aryl groups according to aromatic aldehyde used in the preparation of the first group series compounds.

Prepartion of Stabilized Aluminum Titanate Film via Nonhydrolytic Sol-Gel Route

The stabilized aluminum titanate (Al2TiO5) film was coated on the silicon carbide (SiC) substrate via nonhydrolytic sol-gel method (NHSG), using anhydrous aluminum chloride and titanium tetrachloride as precursors, ethanol as oxygen donor, different iron sources as stabilizers, and dimethyl mixed dibasic acid (DBE) with the characteristic of environmental protection and high boiling point as solvent. The phase transformation of modified Al2TiO5 xerogel during heat treatment, the effect of different iron stabilizers on the stabilization of Al2TiO5 film, and the influence of the coating process parameters on film-forming quality were investigated by means of DTA/TG, XRD and SEM. The results indicate that ethanol iron as the stabilizer, Al2TiO5 crystal phase can be formed at 750°C. While the temperature is raised further to 1000°C, Al2TiO5 is stable without decomposition, and has better synthesis effect. Selecting iron chloride, iron sulfate and iron ethanol as stabilizers respectively, only iron ethanol is effective to thermal stability of Al2TiO5 film. The best optimal vertical sliding velocity is 3.75 mm/s.

Low Temperature Synthesis of Mullite Whisker by Nonhydrolytic Sol-Gel Process Combined with Molten Salt Method

Using tetraethyl orthosilicate and anhydrous aluminum chloride as precursors, ethyl ether as oxygen donor, LiF as mineralizer, and Na2SO4-NaCl as compound molten salt, mullite whisker was synthesized in the low temperature by nonhydrolytic sol-gel process combined with molten salt method. The phase transformation of mixed powder composed of mullite xerogel and molten salt during the heat treatment and the microstructure of mullite whisker corresponding to different temperature were characterized by means of DTA-TG, XRD SEM and TEM. The results show that mullite crystal phase can be formed via non-hydrolytic sol-gel process combined with the molten salt method at 750°C. The synthetic effect of mullite get better as the temperature increased to 850°C, while NaAlSiO4 crystal phase is also detected. Mullite whisker, with diameters ranging from 300~500 nm and lengths of 3~5μm, is prepared at the temperature of 850°C.