A new two series of liquid crystalline Schiff bases containing thiazole moiety with different length of alkoxy spacer were synthesized, and the relation between the spacer length and the liquid crystalline behavior was investigated. The molecular structures of these compounds were performed by elemental analysis and FTIR, 1HNMR spectroscopy. The liquid crystalline properties were examined by hot stage optical polarizing microscopy (OPM) and differential scanning calorimetry (DSC). All compouns of the two series display liquid crystalline nematic mesophase. The liquid crystalline behaviour has been analyzed in terms of structural property relationship
This work includes synthesis of new six membered heterocyclic rings with effective amino group using the reaction of benzylideneacetophenone (chalcone) (1) with thiourea or urea in alcoholic basic medium to form: 1,3-thiazen-2-amine (2), and 1,3-oxazin-2-amine (8) respectively. The diazotization reaction was carried out with sodium nitrite in presence of hydrochloric acid to form diazonium salts which suffered coupling reaction with naphthols and phenols in the presence of sodium hydroxide to form colored azo dyes (4-7, and 10-13). o-methylation reaction of compounds (7) and (10) yielded : 1,3-thiazin -2-yl-diazenyl (14), and 1,3-oxazin-2-yl-diazenyl (15) respectively.The new compounds were characterized using vario
... Show MoreObjectives: Six different Schiff bases were synthesized from ampicillin and amoxicillin with isatin, 5-bromoisatin, and 5-nitroisatin. Methods: Ampicillin and Amoxicillin are linked directly through their α-amino groups to the acyl side chain with isatin and isatin derivatives by nucleophilic addition using glacial acetic acid as a catalyst. Results: chemical structures of these Schiff bases were confirmed using FTIR, 1H NMR and elemental microanalysis. The antibacterial activity was evaluated by measuring minimum inhibitory concentration (MIC) values and showed various degrees of antibacterial activities when compared with parent drugs. Compounds 1a and 2b, which are the Schiff bases of ampicillin and amoxicillin with isatin, showed very
... Show MoreIn this research four steps of the new derivatives of Naproxen drug have been made which are known as a high medicinal effectiveness; the first step involved converting Naproxen into the corresponding ester (A) by reaction Naproxen with methanol absolute in presence H2SO4. While the second step involved treatment methyl Naproxen ester (A) with hydrazine hydrate 80% in presence of ethanol .The third reaction requires synthesis of Schiff bases (C1-C10) by condensation. of Naproxen hydrazide (B) with many substituted aromatic aldehydes . Finally, the fourth step synthesized new tetrazole derivatives ( D1- D10) by the reaction of the prepared Schiff bases (in the third step) with Sodium azide in THF as a solvent .The prepared compounds wer
... Show MoreDiscotic liquid crystal compounds were synthesized and characterized. Liquid crystalline texture of these compounds was investigated by polarized optical microscopy (POM). The Hartree-Fock approximation (HF) was used to calculate theoretical molecular parameters for synthesized compounds such as optimization, hardness, EHOMO, ELUMO, and energy gap using the Gaussian 09W program.
This work comprises the synthesis of new phenoxazine derivatives containing N-substituted phenoxazine starting from phenoxazine (1). Synthesis of ethyl acetate phenoxazine (2) through the reaction of phenoxazine with ethylchloroacetate, which reacted with hydrazine hydrate to give 10-aceto hydrazide phenoxazine (3), then reacted with formic acid to give 10-[N-formyl acetohydrazide] phenoxazine (4). Reaction of compound (4) with phosphorous pentaoxide or phosphorus pentasulphide to gave 10-[N-methylene-1,3,4-oxadiazole] phenoxazine (5) and 10-[N-methylene-1,3,4-thiadiazole] phenoxazine (6).
A new series of Sulfamethoxazole derivatives was prepared and examined for antifibrinolytic and antimicrobial activities. Sulfamethoxazole derivatives bear heterocyclic moieties such as 1,3,4-thiadiazine {3}, pyrazolidine-3,5-diol {4} 6-hydroxy-1,3,4-thiadiazinane-2-thione {5} and [(3-methyl-5-oxo-4,5-dihydro-1H-pyrazol-4-yl)diazenyl] {8}. Their structures were elucidated by spectral methods (FT-IR, H1-NMR). Physical properties are also determined for all compound derivatives. Recently prepared compounds were tested for their antimicrobial activity in the laboratory. Each screened compound showed good tendency to moderate antimicrobial activity.
The compound [G1] was prepared from the reaction of thiosemicarbazide with para-hydroxyphenylmethyl ketone in ethanol as a solvent. Then by sequence reactions prepared [G2] and [G3] compounds. The compound [G4] reaction with ethyl acetoacetoneto synthesized compound [G6] and acetyl acetone to synthesized compound [G5]. Reaction the [G3] with two different types of aldehydes in the present of pipredine to form new alkenes compounds [G7]and [G8].The compound [G3] reacted with hydrazine hydrate to formation[G4] with present the hydrazine hydrade 80% in (10) ml of absolute ethanol. Latter the compound [G4]reacted with different aldehydes with present the glacial acetic acid and the solvent was ethanol to formed the Schiff bases compounds[G9] an
... Show MoreThe compound [G1] was prepared from the reaction of thiosemicarbazide with para-hydroxyphenylmethyl ketone in ethanol as a solvent. Then by sequence reactions prepared [G2] and [G3] compounds. The compound [G4] reaction with ethyl acetoacetoneto synthesized compound [G6] and acetyl acetone to synthesized compound [G5]. Reaction the [G3] with two different types of aldehydes in the present of pipredine to form new alkenes compounds [G7]and [G8].The compound [G3] reacted with hydrazine hydrate to formation[G4] with present the hydrazine hydrade 80% in (10) ml of absolute ethanol. Latter the compound [G4]reacted with different aldehydes with present the glacial acetic acid and the solvent was ethanol to formed the Schiff bases compounds[G9] an
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