Two compounds,[2-amino-4-(4-nitro phenyl) 1,3-thiazole],(4) and [2-amino-4-(4-bromo phenyl) 1,3-thiazole],(5), were synthesized by refluxing thiourea (1) with each of  para-ntiro and para-bomophanacyl bromides(2) and (3) respectively, in absolute methanol. Then, by reaction of [5] with 3,5-dinitrobenzoyl chloride in dimethylformamide (DMF) yielded  (6) .On the other hand, reaction of (4) with chloroacetyl chloride in dry benzene afforded (7), which is  upon treatment with thiourea in absolute methanol, af

    The synthesis , characterization and mesomorphic behaviour of new Nacyl , thiourea and imidazole derivatives which derived from corresponding Schiff bases are reported.             All the synthesized compounds which contain flexible methylene group in the centre of the molecule did not show any liquid crystalline properties . The derivatives of N- acyl [III]e  and thiourea [VI]e  which contain  biphenyl and all compounds with one phenyl in the centre of the molecule display liquid crystalline behaviour .While the imidazoles did not show any liquid crystalline properties except [V]b [V]e  with biphenyl in the centre of the molecule . All th

This article includes designed and synthesized for bent-shaped liquid crystal molecules starting from 5,5-diethylpyrimidine-2,4,6(1H,3H,5H)-trione and two moles of chloroacetylchloride in N, N-dimethyl formamide (DMF) and triethylamine (TEA) to product compound [I] ,then reacted the later compound with two moles of 4-hydroxybenzonitrile to yield nitrile compound [II]. Likewise, reaction 5,5-diethylpyrimidine-2,4,6(1H,3H,5H)-trione and two moles of ethylchloroacetate with fused sodium acetate in ethanol to create an ester compound [III], and then the later compound was reacted with two moles of hydrazine hydrate in ethanol to obtained hydrazide acid compound [IV]. After that, the compound [IV] reacted with two moles of ethyl acetoacetate in

Two series of bent core mesogen containing 1,2,4-traizole ring [X]a-e and [XI]a-e were synthesized by many steps starting from esterification of isophthalic acid with methanol to yield diester compound [I] which was converted to their acid hydrazide [II] and the acid hydrazide reacted with ammonium thiocyanate or phenyl isothiocyanate to yield compounds [III] and [IV] , respectively . Then cyclization by 4% NaOH to yielded 1,2,4 traizole-3- thiol compounds [V] and [VI], respectively, afterword adding hydrazine hydrate to yield compounds [VII] and [VIII] .These compounds condensated with different substituted aldehyde to give new Schiff bases[X]a-e and [XI]a-e,respectively. The synthesized compounds were characterized by melting points ,

     During this paper, new Schiff's base derivatives [F₁-F₅] were prepared through the reaction of dapsone drug with different substituted benzaldehyde compounds. Schiff's bases were then converted into 2,3-dihyroquinazolin-4(1H)-one derivatives [F₆-F₁₀] through the reaction with 2-amino benzoic acid in ethanol. The synthesized compounds were identified by their physical properties using UV-Vis, FT-IR and ¹H-NMR analyses. The liquid crystalline properties of some prepared compounds revealed smectic and nematic phases. Using two separate bacterial species, Pseudomonas aeruginosa (Gram -ve) and Staphylococcus  aureus<

A new compounds of 2,4-substituted-1,3- thiazole containing amines [I] and [II], Schiff bases [IV] and [V], amides [VI]-[X],esters [XI] - [XIII], thiazolidinones [XIV]-[XVIII] and 1,3-oxazepines [XIX]-[XXV] were Synthesized and characterized by melting points, FTIR spectroscopy, elemental analysis, 1HNMR,13CNMR, dept135and Mass spectroscopy. The liquid crystalline properties of the synthesized compounds were verified by using hot-stage polarizing optical microscopy (POM) and differential scanning calorimeter (DSC). The compound [I] was found to be nematic textures (N). The first series of this study [II]n display only enantiotropic nematic phase when n=1-5 while the compounds with n =6-8 display two mesophasese smectic C(SmC) and nematic ph

All new compounds synthesized by many reactions starting from a product the compounds [I]a,b from reaction of 3-phenylenediamine or 4-phenylenediamine with chloroacetyl chloride, then the compounds [I]a,b reacted with potassium thiocyanate to yield compounds [II]a,b. While the compounds[III]a,b yield from reacted the compounds [I]a,b with sodium azide then the compounds [III]a,b reacted 1,3-dipolar cycloaddition reaction with acrylic acid to give compounds [IV]a,b and the later compounds reacted with phenylene diamine to product benzimidazole compounds [V]a,b . In addition to synthesized acid chloride compounds [VI]a,b by reacted the compounds [IV]a,b with thionyl chloride .Finally reacted the compounds [VI]a,b with different aromatic amine

Twelve compounds containing a sulphur- or oxygen-based heterocyclic core, 1,3- oxazole or 1,3-thiazole ring with hydroxy, methoxy and methyl terminal substituent, were synthesized and characterized. The molecular structures of these compounds were performed by elemental analysis and different spectroscopic tequniques. The liquid crystalline behaviors were studied by using hot-stage optical polarizing microscopy and differential scanning calorimetry. All compounds of 1,4- disubstituted benzene core with oxazole ring display liquid crystalline smectic A (SmA) mesophase. The compounds of 1,3- and 1,4-disubstituted benzene core with thiazole ring exhibit exclusively enantiotropic nematic liquid crystal phases.