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.
In this work 2- mercaptobenzothiazole ( 2-MBT ) and some of its derivatives(1, 14 ,27) were prepared by using home made Auto clave .The synthesis involve treatment of 2- MBT or some of its derivatives with chloro acetyl chloride to give 1- chloro acetyl -2- MBT or the corresponding derivatives (2,15,28) . the product was treated with phenyl hydrazine to give the phenyl hydrazide derivatives (3,16,29) . The new derivatives(4-13, 17-26,30-39) were synthesized by reaction of the phenyl hydrazide derivatives with different aromatic aldehydes in the presence of Acetic Acid . Structure of all the prepared compounds confirmation were proved using FTIR , elemental analysis (C .H .N .S ) in addition to melting points.
On the basis of the results which was previously obtained from the structural and the theoretical studies on ~-adrenergic drugs, a series of 2-propanolamine derivatives containing triazole moiety have been prepared and evaluated for their cardiovascular activity . These derivatives were tested by using spontaneously-beating right atria of albino rats.
In this work 2-mercaptobenzoxazole (2-MBO) (1), was prepared by using homemade Auto clave .The synthesis involve treatment of 2-MBO with 2-chloro acetyl chloride to give 2-chloroacetyl thio benzoxazole (2), the product was treated with phenyl hydrazine to give 2-phenyl hydrazide acetyl thio benzoxazole (3). The new derivatives (4-13) were synthesized by reaction of 2-phenyl hydrazide acetyl thio benzoxazole (3) with different aromatic aldehydes in the presence of acetic acid. The compound (2) was treated with hydrazine hydrate to give product (14) then treated with different aromatic aldehydes in the presence of glacial acetic acid to give Schiff bases derivatives (15-24). Structure of all the prepared compounds confirmation were proved
... Show MoreWe 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] with thioglycolic aci
... Show MoreThe Chemistry of heterocyclic sulphur and nitrogen containing compounds have a great role in the field of scientific studies, The 2-amino 5-mercapto-1,3,4-thiadiazole ring for instance, has gained more importance in recent years because they are considered as potent biologically active nucleus. In this study disulfide derivative can be obtained by oxidation with hydrogen peroxide of thiol group of the heterocyclic 2-amino 5-mercapto-1,3,4-thiadiazole ring to obtain compound (3) with expected antibacterial activity. In order to use it as a diazo component to prepare some new bis azo compounds as possible antibacterial agents, the reaction of two primary amino groups on both sides of disulfide dimer with sodium nitr
... Show MoreCompound 4-(((6-amino-7H-[1, 2, 4] triazolo [3, 4-b][1, 3, 4] thiadiazin-3-yl) methoxy) methyl)-2, 6-dimethoxyphenol (6) was synthesized by multi steps. The corresponding acetonitrile thioalkyl (7) was cyclized by refluxing with acetic acid to afford 4-(((6-amino-7H-[1, 2, 4] triazolo [3, 4-b][1, 3, 4] thiadiazin-3-yl) methoxy) methyl)-2, 6-dimethoxyphenol (8). Two new series of 4-(((6-(3-(4-aryl) thioureido)-7H-[1, 2, 4] triazolo [3, 4-b][1, 3, 4] thiadiazin-3-yl) methoxy) methyl)-2, 6-dimethoxyphenol (9a-c) and of 4-(((6-(substitutedbenzamido) 7H-[1, 2, 4] triazolo [3, 4-b][1, 3, 4] thiadiazin-3-yl) methoxy) methyl)-2, 6-dimethoxyphenol (10a-c) were synthesized as new derivatives for fused 1, 2, 4-trizaole-thiadiazine (8). The antioxidant
... Show MoreCompound 4-(((6-amino-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-3-yl)methoxy)methyl)- 2,6-dimethoxyphenol (6) was synthesized by multi steps. The corresponding acetonitrile thioalkyl (7) was cyclized by refluxing with acetic acid to afford 4-(((6-amino-7H-[1,2,4]triazolo[3,4- b][1,3,4]thiadiazin-3-yl)methoxy)methyl)-2,6-dimethoxyphenol (8). Two new series of 4-(((6-(3- (4-aryl)thioureido)-7H-[1,2,4]triazolo[3,4-b][1,3,4] thiadiazin-3-yl)methoxy)methyl)-2,6- dimethoxyphenol (9a-c) and of 4-(((6-(substitutedbenzamido)7H-[1,2,4]triazolo[3,4- b][1,3,4]thiadiazin-3-yl)methoxy)methyl)-2,6-dimethoxyphenol (10a-c) were synthesized as new derivatives for fused 1,2,4-trizaole-thiadiazine(8). The antioxidants of newly compounds were evaluated by DPPH
... Show MoreThe chalcones 1( a,b) were prepared by the reaction of 2- acetyl benzofuran with two aromatic aldehydes in the presence of alkaline media. These chalcones are used as starting material to obtain the desired heterocyclic: pyrazolin, isoxazoline, pyrimidinthion, pyrimidinone, cyclohexanone and indazole derivatives. The structure of newly synthesized heterocyclic compounds were established on the basis of their melting points, elemental analysis(C.H.N), FTIR and 1HMNR (for some of them) spectral data . The synthesized compounds have been screened for their antibacterial activities, they exhibited good antibacterial activity against Escherichia coli (G-) and Staphylococus aureus (G+) .
In this work 5-methylene-yl - (2-methy –oxazole-4-one) (1H) imidazole (1) were synthesized from the reaction of L-Histidine with acetic anhydride and which converted to the of 5-methylene-yl-(2-methyl 3-amino imidazole-4-one)-1H-imidazole (2) by reaction with hydrazine hydrate. Schiff bases (3-6) were synthesized from the reaction of compound (2) with different aromatic aldehyde. Reaction of compounds (3-6) with chloroacetyl chloride gives azetidinone one derivatives (7-10). These compounds were characterized by FT-IR and some of them with 1H-NMR and 13C-NMR spectroscopy.
The article presents the synthesis and liquid crystalline properties of some of new bent and linear core compounds containing a 1,3,4-oxadiazole, piperazine and thiazolidin-4-one rings as a central core. The new synthesized compounds were characterized by elemental analysis and FTIR, ¹HNMR and mass spectroscopy). The liquid crystalline properties were studied by polarized optical microscopy and differential scanning calorimetry. All Schiff bases compounds with 1,3,4-oxadiazole and piprzaine ring in central core presented liquid crystalline properties. The liquid crystallinity of compounds containing 1,3,4-oxadiazole and thiazolidin-4-one rings as a central core were found depending on the type of terminal substituents.