Investigation of mesomorphic properties of new 1,3,4-thiadiazolines (which are synthesised via many steps in Scheme 1) was carried out in this study. These compounds are designed to have a heterocyclic unit, a carboxylate linkage group and a polar ether chain at the end of the molecule adjacent to the benzene ring, which enhance the dipolar interactions forces (varied from one to eight carbons) to investigate the association properties of their phases. The structure of the target compounds and the intermediates were confirmed by 1H NMR, 13C NMR, mass and FTIR spectral techniques. Polarised microscopic studies revealed that all the compounds in the series exhibited enantiotropic liquid crystalline properties. This was further confirmed using differential scanning calorimetric experiments. The synthesised compounds type [V]n in this study displayed different liquid crystalline mesophases and the homologous [V] having an alkoxy terminal group (n = 1–3) exhibited nematic phase, whilst the last derivatives of the series (4–8), displayed smectic A phase.
We described herein the synthesized and characterized of new bent and liner core compounds containing thiazolidin-4-one ring[XI-XIII] and [XIV-XVI] respectively. These compounds synthesized by sequence reactions starting from reaction resorcinol or hydroquinone with chloracetyl chloride to yield compounds [I] and [II] ,then the later compounds reactant with 4-hydroxybenzylaldehyde to product dialdehyde compounds [III] and [IV] .The Schiff bases compounds[V-VII] and [VIII-X] synthesized from reaction the compound [III] or [IV] with different aromatic amines, while the bent and liner core mesogens containing thiazolidin-4-one ring [XI-XIII] and [XIV-XVI] synthesized from reaction Schiff bases compounds[V-VII] or [VIII-X]
... Show MoreIn this work ester derivatives were synthesized by the reaction of imidazole derivatives (C1) with ethylchloroacetate in ethanol and NaOH to give the corresponding (C2) .While compound (C3) acetohydrazide was synthesized by the reaction of ester derivatives (C2) with hydrazine hydrat in ethanol. Compound (C3) from the reaction with different aromatic aldehydes in absolute ethanol gave the Schiff′s bases (C4,C5). The product compounds were characterized by FT-IR, U.V and 1HNMR spectra and the biological activities were studied as antibacterial.
This work involves synthesis of novel Schiff bases derivatives contining isoxazoline or pyrazoline units starting with chalcons . 4-Aminoacetophenone was reacted with 3-nitrobenzaldehyde in basic medium giving chalcone [I] by claisen-schemidt reaction. The chalcone [I] was reacted with hydroxylamine hydrochloride giving isoxazoline [II] in basic medium. The chalcone [I] could also react with hydrazitne hydrate to give pyrazoline [III] . The novel Schiff bases with structural formula [IV] and [V] were prepared by the reaction of amino compounds ; isoxazoline [II] and pyrazolines [III] with p-substituted aldehydes or p-subsituted ketones, respectively in dry benzene using drops of glacial acetic acid as a cat
... Show MoreIn this paper a new series of morpholine derivatives was prepared by reacting the morpholine with ethyl chloro acetate in the presence triethylamine as a catalyst in benzene gave morpholin-N-ethyl acetate(1) which reacted with hydrazine hydrate in ethanol, and gave morpholin-N-ethyl acetohydrazide (2) . Morpholin-N-aceto semithiocarbazide (3) were prepared by reacting compound(2) with ammonium thiocyanate , concentrated hydrochloric acid and ethanol as a solvent .Compound (3) reacted with sodium hydroxide and hydrochloric acid to give 5-(morpholin-N-methylene)-1H-1,2,4-triazole-3-thiol (4) .The new series of 1,2,4-triazol derivatives (5-8) was synthesized by reaction of compound(4) with formaldehyde , DMF as a solvent and different
... Show MoreIn this study, Schiff's bases [S3,S4] were synthezied by condensation of N,N-dimethyl amino benzaldehyde with primary aromatic amine[N-(hydrazinyl methyl)benzamide]. These Sciff's bases were found to react with maleic anhydride and phthalic anhydride to give 1,3Oxazepine[S5,S6,S7,S8] in good yields. The structures confired by m.p ,T.L.C.,FT.IR and 1H-NMR (of some of them).
In this paper the new starting material 2-(5-chloro-1H-benzo[d]imidazole-2-yl) aniline (1) was synthesized by the condensation reaction of 4-chloro-o-phenylenediamine and anthranilic acid .The new Mannich base derivatives were synthesized using formaldehyde and different secondary amines to synthesize a new set of benzimidazole derivatives(2-5). Also, the new Schiff-base derivatives (6-10) were synthesized from the reaction of compound (1) with various aromatic aldehydes and the closure-ring was done successfully using mercapto acetic acid to get the new thiazolidine derivatives(11-12).These new compounds were characterized using some physical techniques like:FT-IR Spectra and 1HNMR Spectra.
This work contain many steps starting from esterification of isophthalic acid to yield diester compound [I] which was converted to their acid hydrazide [II], then the later compound reacted with ethylacetoacetate to yield pyrazol-5-one compound [III]. Afterword added acetyl chloride to give the compound [IV], thereaction of this compound with theiosemicarbazide ledto produce a new carbothioamide compound [V], Which was reacted with ethyl chloro acetate to yield thethioxoimidazolidin compound [VI]. The condensation reaction of this compound with different substituted aldehyde give new alkene derivatives[VII]a-d. The synthesized compounds were characterized by melting points , FT-IR ,1H-NMR and Mass spectroscopy .
This research included the preparation of 2-mercaptobenzoxazole (N1) by the reaction of ortho-aminophenol with carbon disulfide in an alcoholic potassium hydroxide solution. The 2-mercapto benzoxazole (N1) was then treated with hydrazine to obtain the 2-hydrazino benzoxazole (N2). A number of hydrazones (N3-N5) were prepared through the reaction of N2 with different benzaldehydes. The compound (N6) was also prepared whereby the ring closing of hydrazone (N3) using chloroacetylchloride, while the compound (N7) was prepared by treating 2-hydrazino benzoxazole with acetylacetone. When the compound (N1) was treated with formaldehyde, it afforded the compound (N8). Also, the N9 was obtained from the reaction of N1 with chloroacetic acid in th
... Show MoreNitrogen heterocycles are of a special interest because they constitute an important class of natural and non natural products, many of which exhibit useful biological activities.Among these nitrogen heterocycles are 1, 3, 4-thiadiazole containing compounds. The therapeutic effects of these derivatives have been well studied for a number of pathological conditions including inflammation, pain, or hypertension. Moreover, synthesis of thiadiazoles has attracted wide-spread attention due to their diverse applications as antibacterial, anticancer, antifungal anti-inflammatory and antidepressant agents.According to this information’s new derivatives of 1, 3, 4-thiadiazole were designed and synthesized and in the hope of having some act
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