4-Quinolone-Carboxamide and Carbothioamide Compounds as Fluorescent Sensors. New Fluorimetric Methods for Cu and Fe Determination in Tap Water and Soil.

Ion sensor properties of the carboxamide and carbothioamide compounds carrying 4-quinolone group were investigated by means of emission spectrometry in methanol-water (1:1). The compounds were selectively complexed with Cu, Pd, and Fe among many metal ions. The complex stoichiometry and the stability constant were determined by fluorimetric measurements.

Piperazine-azole-fluoroquinolone hybrids: Conventional and microwave irradiated synthesis, biological activity screening and molecular docking studies.

A series of new 1,2,4-triazole and 1,3,4-oxadiazole derivatives was obtained via several steps sequential reactions of phenyl piperazine. Then, these compounds were converted to the corresponding fluoroquinolone hybrids via one pot three component Mannich reaction. All the reactions were examined under conventional and microwave mediated conditions, and optimum conditions were determined.

Synthesis, biological activity and structure activity relationship studies of novel conazole analogues via conventional, microwave and ultrasound mediated techniques.

1,2,4-Triazole derivatives containing a piperazine nucleus (4a-d and 10) were prepared starting from 1-(2-methoxyphenyl)piperazine or ethyl 4-(4-amino-2-fluorophenyl)piperazine-1-carboxylate via several steps. The synthesis of fifteen compounds (7a-l and 13a-c), which can be considered as new analogues of azole class antifungals was performed starting from 1,2,4-triazoles (4a-d and 10) via three steps containing the condensation with 2-bromo-1-(4-chlorophenyl)ethanone, reduction of carbonyl group to alcohol and alkylation of OH group, respectively. All the reactions were examined under conventional, ultrasound and microwave irradiation conditions as green chemistry techniques, and optimum conditions were defined.

Conventional and microwave prompted synthesis, antioxidant, anticholinesterase activity screening and molecular docking studies of new quinolone-triazole hybrids.

The synthesis of ethyl 4-oxo-1,4-dihydroquinoline-3-carboxylates (4, 5) was performed via the reaction of corresponding anilines with diethyl ethoxymethylenemalonate under conventional and also microwave promoted conditions. The treatment of 4 and 5 afforded the corresponding hydrazides (6 and 7). These hydrazides were converted to the corresponding carbo(thio)amides (9a-f and 10a-e) which were then subjected to an intramolecular cyclisation leading to the formation of quinolone-triazole hybrids (11a-f and 12a-e).

The electrochemical and spectroelectrochemical properties of metal free and metallophthalocyanines containing triazole/piperazine units.

The synthesis and characterization of novel peripherally tetra [1,2,4]-triazole substituted metal-free phthalocyanine and its metal complexes (Zn(II), Ni(II), Pb(II), Cu(II) and Fe(II)) and the investigation of electrochemical and spectroelectrochemical properties of metal-free, Zn(II), Pb(II), Fe(II) phthalocyanines were performed for the first time in this study. Electrochemical characterizations of the complexes were performed with voltammetric and in situ spectroelectrochemical measurements. Voltammetric responses of the complexes supported the proposed structures, since complexes bearing redox inactive Pc ring metal centers just gave Pc based electron transfer reactions, while iron phthalocyanine went to metal based electron transfer reaction in addition to the Pc based ones.

Synthesis of somenew hybride molecules containing several azole moieties and investigation of their biological activities.

1,2,4-Triazole-3-one prepared from tryptamine was converted to the corresponding carbotioamides by several steps. Their treatment with ethyl bromoacetate or 4-chlorophenacyl bromide produced the corresponding 5-oxo-1,3-thiazolidine or 3-(4-chlorophenyl)-1,3-thiazole derivatives. Acetohydrazide derivative that was obtained starting from tryptamine, was converted to the corresponding Schiff basis and sulfonamide by the treatment with suitable aldehydes and benzensulphonyl chloride, respectively.

Microwave-assisted synthesis of some hybrid molecules containing penicillanic acid or cephalosporanic acid moieties and investigation of their biological activities.

Ethyl 4-amino-2-fluorophenylpiperazin-1-carboxylates containing a 1,3-oxazol(idin)e, 5-thioxo-1,2,4-triazole, 1,3,4-thiadiazole, 5-thioxo-1,3,4-oxadiazole, or 1,3-thiazole nucleus were obtained starting from ethyl piperazine-1-carboxylate () by several steps. The treatment of amine, or hydrazide, with several aromatic aldehydes generated the corresponding arylmethyleneamino (-) or arylidenehydrazino (-) compounds. The Mannich reaction between the 1,2,4-triazole or 1,3,4-oxadiazole compounds and 7-aca produced cephalosporanic acid derivatives.

Synthesis of some heterofunctionalized penicillanic acid derivatives and investigation of their biological activities.

6-Substituted amino-penicillanic acid esters were synthesized starting with 6-apa. The compounds containing a 1,3-thiazole- or 1,3-thiazolidinone nucleus linked to the penicillanic acid skeleton via a hydrazino linkage were obtained from 6-apa. The treatment of carbonylamino and carbonothioylamino compounds with 4-chlorophenacyl bromide or ethyl bromoacetate gave 6-bis{4-[1,3-thiazol(idinone)amino]benzoyl}amino derivatives of 6-apa.

Design, synthesis and biological activities of some 7-aminocephalosporanic acid derivatives.

The treatment of 7-ACA with 4-substituted benzensulfonyl chlorides afforded the compounds containing 4-nitro/aminophenyl sulfonylamino moiety in the cephalosporanic acid skeleton (2, 4). The synthesis of the cephalosporanic acid derivatives containing 1,3-thiazole or 5-oxo-1,3-thiazolidine nucleus and sulfonamide function (8a, 8b, 10) was performed starting from 7-ACA by several steps. The reaction of 7-ACA with [4-(2-fluoro-4-nitrophenyl)piperazin-1-yl]acetyl chloride afforded the corresponding 7-{[4-(2-fluoro-4-nitrophenyl)piperazin-1-yl]acetyl}amino derivative (13).

Syntheses and biological activities of new hybrid molecules containing different heterocyclic moieties.

4-Aryl-5-(pyridin-3-yl)-4H-1,2,4-triazole-3-(thi)oles 5-7, obtained starting from nicotinic acid hydrazide were converted to the corresponding Mannich bases 12-24 by the reaction with several heterocyclic amines in the presence of formaldehyde. The synthesis of S-alkylated compounds 8-11 was performed from the reaction of the corresponding triazol-5-thioles with various alkyl halides. The condensation of carbo(thio)amides 2-4 with 4-chlorophenacyl bromide afforded the corresponding 1,3-thia(oxa)zol-2(3H)-ylidene]pyridine-3-carbohydrazides 25-27.

Microwave assisted synthesis of some hybrid molecules derived from norfloxacin and investigation of their biological activities.

Norfloxacin was converted to 7-(4-amino-2-fluorophenyl)piperazin derivative (2) via the formation of nitro compound. The synthesis of the norfloxacin derivatives containing 1,3-thiazole or 1,3-thiazolidin moiety was performed from the reaction of 4-chlorophenacylbromide or ethyl bromoacetate with compounds 4-7 obtained starting from 2. 3-Fluoro-4-[4-(2-methoxyphenyl)piperazin-1-yl]aniline (14), 5-{[4-(2-methoxyphenyl)piperazin-1-yl]methyl}-4-phenyl-4H-1,2,4-triazole-3-thiol (18) and {[4-(2-methoxy phenyl)piperazin-1-yl]methyl}-1,3,4-oxadiazol-2-thiol (19) were obtained starting from 1-(2-methoxyphenyl)piperazine by several steps.

Antimicrobial and antiurease activities of newly synthesized morpholine derivatives containing an azole nucleus.

2-[6-(Morpholin-4-yl)pyridin-3-ylamino]acetohydrazide () was obtained starting from 6-morpholin-4-ylpyridin-3-amine () via the formation of ester () and then converted to the corresponding Schiff bases () with the reaction with aromatic aldehydes. The carbothioamide (), obtained from the reaction of hydrazide with phenylisothiocyanate, was converted to the corresponding 1,2,4-triazole () and 1,3,4-thiadiazole () derivatives by the treatment with NaOH or HSO, respectively. The cyclocondenzation of with 4-chlorophenacyl bromide or ethyl bromoacetate produced the corresponding 1,3-thiazole () or 1,3-thiazolidine derivatives (), respectively.

Design, synthesis and antimicrobial activities of some azole derivatives.

Three new 1,3,4-oxadiazole, 1,3-thiazolidine and 1,2,4-triazole derivatives were obtained starting from furan-2-carbohydrazide. Then, 1,2,4-triazole compound was converted to the corresponding Mannich bases using several secondary amines including piperidine, piperazine, morpholine or thiomorpholine moiety. The synthesis of 5-(furan-2-yl)-4-{[(4-methoxyphenyl)methylidene]amino}-4H-1,2,4-triazole-3-thiol (XIII) was performed starting from furan-2-carbohydrazide by three steps.

Cyclization of some carbothioamide derivatives containing antipyrine and triazole moieties and investigation of their antimicrobial activities.

Acetohydrazide derivative containing both antipyrine and triazole nuclei (5) was obtained starting from ethyl hydrazinecarboxylate derivative (2) and 4-aminoantipyrine (1) by three steps. The treatment of compound 5 with CS(2) afforded the conversion of hydrazide function into 5-mercapto-1,3,4-oxadiazole ring leading to the formation of 7. Then, 7 gave the product containing triazolotriazine moiety (9) by the reaction with hydrazine hydrate.

Synthesis and antimicrobial activities of some new 1,2,3-triazole derivatives.

Some novel 4,5-disubstituted-2,4-dihydro-3H-1,2,4-triazol-3-one (3, 6, 8, 9) derivatives and or 3-(4-methylphenyl)[1,2,4]triazolo[3,4-b][1,3]benzoxazole (5) were synthesized from the reaction of various ester ethoxycarbonylhydrazones (1a-e) with several primary amines. The synthesis of 4-amino-5-(4-chlorophenyl)-2-[(5-mercapto-1,3,4-oxadiazol-2-yl)methyl]-2,4-dihydro-3H-1,2,4-triazol-3-one (13) was performed starting from 4-Amino-5-(4-chlorophenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (2) by four steps; then 13 was converted to the corresponding Schiff base (14) by using 4-methoxybenzaldehyde. Finally, two Mannich base derivatives of 14 were obtained by using morpholine or methyl piperazine as amine component.

Synthesis of some new 1,2,4-triazoles starting from isonicotinic acid hydrazide and evaluation of their antimicrobial activities.

5-Pyridin-4-yl-1,3,4-oxadiazole-2-thiol (2) was obtained from the reaction of isonicotinic acid hydrazide with carbon disulfide in basic media and converted into 4-amino-5-pyridin-4-yl-4H-1,2,4-triazole-3-thiol (5) by the treatment with hydrazine hydrate. The synthesis of 3 and 6 was performed from the reaction of 2 and 5 with ethyl bromide. The treatment of 5 with 4-fluorobenzaldehyde or indol-3-carbaldehyde resulted in the formation of 4-[(arylmethylene)amino]-5-pyridin-4-yl-4H-1,2,4-triazole-3-thiols (7a and 7b).

Synthesis of some new 1,3,4-thiadiazol-2-ylmethyl-1,2,4-triazole derivatives and investigation of their antimicrobial activities.

4-Amino-2-[(5-arylamino-4,5-dihydro-1,3,4-thiadiazol-2-yl)methyl]-5-(4-methylphenyl)-2,4-dihydro-3H-1,2,4-triazol-3-ones (3a-c) were obtained in acidic media via the formation of 2-[(4-amino-3-aryl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)acetyl]-N-arylhydrazinecarbothioamides (2a-c), and then, compound 3b was converted to methylated derivative, 4. The basic treatment of carbothioamide derivatives, 2a-c, afforded 4-amino-2-[(4-aryl-5-sulphanyl-4H-1,2,4-triazol-3-yl)methyl]-5-(4-methylphenyl)-2,4-dihydro-3H-1,2,4-triazol-3-ones (5a-c). The alkylation reactions of compounds 4H-1,2,4-triazol-3-ylmethyl-5-(4-methylphenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one derivatives (5a-c) were performed by using methyl iodide or ethyl bromide in the presence of sodium ethoxide, while the treatment of the same intermediates, 5a-c, with aromatic aldehydes produced 2-{[4-(4-aryl)-5-sulphanyl-4H-1,2,4-triazol-3-yl]methyl}-4-(arylmethylene)amino-5-(4-methylphenyl)-2,4-dihydro-3H-1,2,4-triazol-3-ones (8a-d).

Synthesis of some new 1,2,4-triazoles, their Mannich and Schiff bases and evaluation of their antimicrobial activities.

4-Phenyl-5-pyridin-4-yl-4H-1,2,4-triazole-3-thiol (3) was obtained in basic media via the formation of 2-isonicotinoyl-N-phenylhydrazinecarbothioamide (2), and converted to some alkylated derivatives (4a,b) and Mannich base derivatives (5a-c). 2-[(4-Phenyl-5-pyridin-4-yl-4H-1,2,4-triazol-3-yl)thio]acetohydrazide (7) that was obtained by using compound 3 as precursor in two steps was converted to thiosemicarbazide derivative (8), Schiff base derivatives (9) and 5-{[(4-phenyl-5-pyridin-4-yl-4H-1,2,4-triazol-3-yl)thio]methyl}-1,3,4-oxadiazole-2-thiol (10). Moreover, 5-{[(4-phenyl-5-pyridin-4-yl-4H-1,2,4-triazol-3-yl)thio]methyl}-3-{[(2-morpholin-4-ylethyl)amino]methyl}-1,3,4-oxadiazole-2(3H)-thione (11) was synthesized via reaction of compound 10 with 2-(4-morpholino)ethylamine.

Synthesis and antimicrobial activities of some new 1-(5-phenylamino-[1,3,4]thiadiazol-2-yl)methyl-5-oxo-[1,2,4]triazole and 1-(4-phenyl-5-thioxo-[1,2,4]triazol-3-yl)methyl-5-oxo- [1,2,4]triazole derivatives.

Acetic acid ethyl esters containing 5-oxo-[1,2,4]triazole ring (2) were synthesized by the condensation of compounds 1a-f with ethyl bromoacetate in basic media. The reaction of compounds 2a-f with hydrazine hydrate led to the formation of acid hydrazides (3a-f). The treatment of compounds 3 with two divers aromatic aldehydes resulted in the formation of arylidene hydrazides as cis-trans conformers (4a,c,e,f, 5a,e,f).

Synthesis of 3-alkyl(aryl)-4-alkylidenamino-4,5-dihydro-1H-1,2,4-triazol-5-ones and 3-alkyl-4-alkylamino-4,5-dihydro-1H-1,2,4-triazol-5-ones as antitumor agents.

A series of 3-alkyl-4-phenylethylidenamino- (8) and 3-alkyl-4-(3-phenylallylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones (9) was synthesized from the reaction of the corresponding 3-alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (1), with phenylacetaldehyde and cinnamaldehyde. 3-Alkyl-4-(2-phenylethylamino)- (10) and 3-alkyl-4-(3-phenylpropylamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones (11) were obtained from the selective reduction of compounds (8) and (9) with NaBH(4). The in vitro antitumor activity of the novel compounds was screened and the highest inhibition of tree tumor cell lines was observed for the compounds containing phenylethylenamino and phenylethylamino groups at position 4 of 1,2,4-triazol ring.