Quantitative structure-property relationship study of the solubility of thiazolidine-4-carboxylic acid derivatives using ab initio and genetic algorithm-partial least squares

A quantitative structure-activity relationships （QSAR） study is suggested for the prediction of solubility of some thiazolidine-4- carboxylic acid derivatives in aqueous solution. Ab initio theory was used to calculate some quantum chemical descriptors including electrostatic potentials and local charges at each atom, HOMO and LUMO energies, etc. Modeling of the solubility of thiazolidine- 4-carboxylic acid derivatives as a function of molecular structures was established by means of the partial least squares （PLS）. The subset of descriptors, which resulted in the low prediction error, was selected by genetic algorithm. This model was applied for the prediction of the solubility of some thiazolidine-4-carboxylic acid derivatives, which were not in the modeling procedure. The relative errors of prediction lower that -4% was obtained by using GA-PLS method. The resulted model showed high prediction ability with RMSEP of 3.8836 and 2.9500 for PLS and GA-PLS models, respectively.

Structure and Biological Activities of 3-Phenyl-2-[1-benzoyl-1-(1,2,4-triazol-1-yl)] Methenyl Thiazolidine

The title compound 3-phenyl-2-[1-benzoyl-1-(1,2,4-triazol-1-yl)]methenyl thiazolidine was synthesized from acetophenone,triazole,phenylthioisocyanate and 1,2-dibromo-ethane by several step reactions. Its structure was identified by means of 1H NMR,MS and IR spectrometries. The single crystal structure of \{3-phenyl\}-2-[1-benzoyl-1-(1,2,4-triazol-1-yl)]methenyl thiazolidine was determined by X-ray diffraction. The preliminary bioassays have shown that the title compound exhibits the weak activities of fungicide and plant growth regulator.

Thiazolidine Derivatives as Chiral Catalysts in the Enantioselective Addition of Diethylzinc to Benzaldehyde

Four types of chiral thiazolidine derivatives were synthesized conveniently from natural L-cysteine and showed good enantioselectivity in up to 90% ee in the addition of diethylzine to benzaldehyde. Their enantioselectivity was affected by the bulkiness of R and the thiazolidine ring systems in their molecules.

Resolution of racemic R.S-α-arylethylamine by a new resolving agent (R)thiazolidine-2-thione-4-carboxylic acid

Racemic R.S α arylethylamine was resolved by R（-）thiazolidine 2 thione 4 carboxylic acid, a new resolving agent abbreviated as , by which R（-）TTCA·S（-） arylethylamine salts 2a - 2e, 20 D= -47.24°\-64.40° and optically active R（+） α arylethylamines 3a - 3e , 74.54%\94.45% e.e., were obtained. Optically active S（-） α arylethylamines 4a - 4e , 72.84%\90.36% e.e., were obtained by the decomposition of 2a - 2e in basic solutions. The influence of substitutive group of the benzene ring on the basicity of the amino group was studied by semiempirical PM3 method. The structures of the R（-）TTCA·S（-） α phenylethylamine salt （2a（R S） configuration） and R（-）TTCA·R（+） α phenylethylamine salt （2a′（R R） configuration） have been established by means of X ray diffraction. They crystallize in a monoclinic system. Space group is P 2 l. The cell constants of 2a（R S） configuration were obtained as follows: a =1.387 8（2）, b =0.664 05（10）, c =1.580 0（2） nm; β =90 844（10）°, Z=4 ; those obtained for 2a′（R R） configuration were a= 1.080 6（2）, b =0.584 80（12）, c = 1.218 8（2） nm, β =110.38（3）°, V =0.722 0 nm 3, Z =2. There are intermolecular hydrogen bonds in the crystals of the two kinds of configurations of the amine salt. The hydrogen bond number in the unit cell of R（-）TTCA·S（-） α phenylethylamine salt is twice as much as that of R（-）TTCA·R（+） α phenylethylamine salt.

Application of chiral thiazolidine ligands to asymmetric hydrosilation

Seven chiral thiazolidines bound rhodium complexes were synthesized and their catalytic asymmetric hydrosilation properties were investigated It was found through investigation that the configuration of newly formed chiral centre C2 of substituted chiral thiazolidines prepared from L-cysteine or its esters has no effect on the final results of catalytic asymmetric hydrosilation.The direct reason for causing this phenomenon is reported by the present quantitative results for the first time:the rapid racemation of chiral center C2 of chiral thiazolidine ligands takes place under the catalysis of rhodium(Ⅰ) complex [Rh(COD)

Fatty Acids in Heterocyclic Synthesis. Part XVII: Synthesis of Non Ionic Surfactants Containing Piperidine, Piperazine, Imidazole Based on Thiadiazole and Microbiological Activities Evaluation

A series of novel scaffolds Thiadiazolyl Piperidine, Thiadiazolyl Piperazine, thiadiazolidine, Thiadiazolyl thiazole and Thiadiazolyl-imidazole-Thione were synthesized from cheap, available and biologically active stearic acid. 2-amino-5-heptadecyl 1,3,4-thiadiazole reacts with chloroacetyl chloride and produced 2-choloro-N-(5-heptadecyl-1,3,4-Thiadiazole-2-yl) acetamide. Which allowed to react with Piperidine, Piperazine, urea and/or Thiourea and Potassium thiocyanate, and the latest scaffolds have been synthesized, respectively, and the structures of these compounds were established by elemental analysis, MS, IR and 1H-NMR spectral data. The antimicrobial activities of the synthesized compounds were evaluated in-vitro against strains of gram +ve, gram -ve bacteria and fungi. Nonionic surfactant were obtained by addition of different moles of propylene oxide (3,5,7 mole) to the synthesized compounds bearing an active hydrogen. Physico-chemical and surface properties as well as biodegradability of the synthesized non-ionic surfactants were evaluated.