Synthesis, characterization, and antimicrobial activity of novel hydrazone-bearing tricyclic quinazolines (original) (raw)
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Synthesis and Antimicrobial Activity of Some Novel Hydrazinyl Quinazoline Amine Derivatives
2-chloro-4-aminoquinazolines 3a-b were synthesized by intramolecular cyclization of substituted formamide 2a-b in presence of phosphorus oxychloride in one pot. These were further condensed with 5-aryl/alkyl-2-hydrazino-1,3,4thiadiazoles 8a-e. synthesized by condensation of hydrazine hydrate with 2-chloro-5-aryl/alkyl-1,3,4-thiadiazoles 7a-e which in turn were obtained by copper mediated diazotization of 2-amino-5-aryl/alkyl-1,3,4-thiadiazoles 6a-e in acetic acid to give various 2-[2-(1,3,4-thiadiazol-2-yl)hydrazinyl] quinazolin-4-amines 9a-l. The structures of the compounds have been confirmed by elemental analysis and spectral analysis. Newly synthesized compounds were screened for their antimicrobial activities.
Synthesis and Characterization of New Quinazolines as Potential Antimicrobial Agents
ChemInform, 2007
Ethyl 4-[2-(2-chlorophenyl)-4-oxo-3-hydroquinazolin-3yl]benzoate 1 which reacts with hydrazine hydrate in presence of methanol resulted into N-amino{4-[2-(2-chlorophenyl)-4-oxo(3hydroquinazolin-3-yl)phenyl}carboxamide 2. Compound 2 on treatment with aryl isothiocyanates in presence of acetone is converted into aryl-N-{[({4-[2-(2-chlorophenyl)-4-oxo(3-hydroquinazolin-3-yl)]phenyl}carbonylamino)amino]thioxo methyl}amides 3. Compound 3, in presence of sulphuric acid has yielded aryl-N-(5-{4-[2-(2-chlorophenyl)-4-oxo(3-hydroquinazolin-3-yl)]-phenyl}(1,3,4,thiadiazol-2-yl))amides 4a-l. Newly synthesized compounds 4a-l have been screened for their antibacterial and antifungal activities on Eschericia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Staphylococcus pyogenes, C. albicans, A. niger and A. clavatus.
Synthesis, Characterization and Anti-Microbial Evaluation of a Series of Quinazoline Analogs
Journal of Advanced Scientific Research
A series of substituted 6-bromo-3-(3-chloro-2-oxo-4-arylazetidin-1-yl)-2-methylquinazolin-4(3H)-one has been synthesized and evaluated for their biological activity. The title compounds (G1-G10) were prepared by the reaction of 5- bromo anthranilic acid with acetic anhydride to form 6-bromo-2-methyl-4H-benzo[1,3]oxazin-4-one which upon treatment with hydrazine hydrate in the presence of anhydrous pyridine form 3-amino-6-bromo-2-methylquinazolin- 4(3H)-one. The resulting intermediate underwent Schiff reaction with different aromatic aldehyde followed by reflux with chloroacetyl chloride and triethylamine. Ten different quinazoline derivatives (G1-G10) were synthesized. Structural assignments of these compounds have been made by elemental analysis, FTIR, 1HNMR 8 Mass spectral data and the purity of the compounds was determined by TLC. The anti-microbial activity of the newly isolated heterocyclic compounds was evaluated against Gram-positive, Gram-negative bacteria and fungi. Most of ...
Revista de Chimie, 2020
A novel series of 3-, 4-substituted, and 3,4-di substituted quinazoline derivatives were prepared via various cyclized regents and most of the newly prepared compounds evaluated for their antimicrobial activities in vitro against Gram-positive, Gram-negative bacterial strains and fungi strains. The structures of the quinazoline derivatives have been confirmed using spectroscopic analyses (IR, NMR, and EI-MS). Some of the synthesized derivatives displayed a moderate antimicrobial activity in comparison with reference drugs, for example compounds 13d, 15a, 17b, 18b, 18d, 25, and 29a-c. Among the synthesized compounds, the pyrimidoqunazoline derivative 6c elicited the highest activity.
The title compounds have been prepared by incorporating the anthranilic acid with substituted benzoylchloride which lead to the formation of oxazin-4-ones followed by subjecting it in the presence of pyridine, hydrazine hydrochloride, sodium cyano oxide lead to the formation of 1-(4-oxo-2-arylquinazolin-3(4H)-yl) semicarbazide. Various aromatic carbonyl compound with 1-(4-oxo-2-arylquinazolin-3(4H)-yl) semicarbazide in the presence of glacial acetic acid and ethanol gives (S1-S10) quinazoline derivatives. Structures of newly synthesized compound have been established on the basis of their IR and NMR spectral data. All the synthesized compounds have been screened for their antimicrobial activity.
Molecules, 2012
A simple strategy for the synthesis of the hitherto unreported 3-arylazo-4phenyl-[1,2,4]triazepino[2,3-a]quinazoline-2,7(1H)-diones is described. Spectral data indicated that the studied compounds exist predominantly in the hydrazone tautomeric form. The antimicrobial activity of the newly synthesized compounds was also evaluated. The results indicated that some of these compounds have moderate activity towards bacteria.
Scientia Pharmaceutica, 2004
A series of quinoxaline derivatives has been synthesized by reacting 3hydrazinoquinoxalines 1a,b with many bifunctional reagents. Reaction of 1a,b with chloroacetyl chloride and ethyl chloroacetate afforded 1-chloromethyl [I .2.4]tnazoIo[4.3-alquinoxalines 2a,b and dihydro[l,2,4]triazino[4,3-alquinoxalin-2-ones 3a,b respectively. Condensation of 1a,b with ethyl acetoacetate and acetylacetone yielded 2-quinoxalinylhydrazonobutanoates 4a,b and 2quinoxalinylhydrazono-2-pentanones 5a,b respectively. Cyclization of 5a,b gave 3,5-dimethylpyrazolylquinoxalines 6a,b. Moreover, reaction of compounds 2a,b with N-phenyl piperazine derivatives afforded 4-(4-Arylpiperazin-1-yl)-1-[(4arylpiperazin-1-yl) methyl)]triazoloquinoxalines 7a+. The prepared compounds were screened for In vitro antibacterial and antifungal activities. None of the tested compounds showed significant activity towards Pseudomonas aeruginosa. However, remarkable activities were noticed for compounds 5a and Sb against Eschenchia coli. Staphylococcus aureus and Candida albicans. Compounds 6a and 6b lacked any antimicrobial activities against the tested microorganisms.
Antimicrobial and Cytotoxic Evaluation of New Quinazoline Derivatives
Natural Product Communications, 2016
The synthesis of nine new quinazoline derivatives (2a-2i) and evaluation of their antimicrobial and cytotoxic activities were aims of the present work. For the synthesis of the compounds, 2-chloro-6,7-dimethoxyquinazolin-4-amine was used as the initial starting material. The intermediate product, 2-hydrazinyl-6,7-dimethoxyquinazolin-4-amine, was reacted with appropriate aromatic aldehydes to obtain 2-(2-benzylidenehydrazinyl)-6,7-dimethoxyquinazolin-4-amine derivatives as final compounds. The structures of the compounds were elucidated by 1H- and 13C-NMR, IR, and MS analyses. The new pure compounds were evaluated for their potential antimicrobial and cytotoxic activities using in vitro microdilution and cell culture techniques, respectively. The compounds 2e and 2f may be promising candidates for the treatment of fungal infections with their activity and cytotoxicity.
Journal of Saudi Chemical Society, 2018
The quinoline hydrazone ligands were synthesized through multi-step reactions. The 2-hydroxy-3-formylquinoline derivatives (1a-1c) were prepared from acetanilide derivatives as starting materials using Vilsmeier-Haack reaction. Then the condensation of 2-hydroxy-3formylquinoline derivatives with hydrazide derivatives (2a-2c) yielded quinoline hydrazone ligands (3a-3i). The synthesis of a new series of Zn(II) complexes carried out by refluxing with these quinoline hydrazone ligands (3a-3i) is reported. The molecular structures of the ligands (3a-3i) and the Zn complexes were characterized by elemental analysis and spectral studies like FT-IR, 1 H and 13 C NMR, MS, UV-Visible and fluorescence. The preliminary results of antituberculosis study showed that most of the Zn(II) complexes 4a-4i demonstrated very good antituberculosis activity while the ligands 3a-3i showed moderate activity. Among the tested compounds 4e and 4g were found to be most active with minimum inhibitory concentration (MIC) of 8.00 lM and 7.42 lM respectively against Mycobacterium tuberculosis (H37 RV strain) ATCC No-27294 which is comparable to ''first and second line" drugs used to treat tuberculosis.
Synthesis and Antimicrobial Activity of Tricyclic Quinazolinethiones
Pharmaceutical Chemistry Journal, 2017
Deoxyvasicine thione (III) and mackinazoline thione (6,7,8,9-tetrahydro-11H-pyrido[2,1-b]quinazoline-11-thione, IV) were synthesized and condensed with aromatic and heterocyclic aldehydes at the a-methylene [CH 2-3 (III) or CH 2-6 (IV)]. Either 3-and 6-arylidene derivatives (V-XIII) or 6-hydroxymethylaryl derivatives (XIV) were formed depending on the reaction conditions. Formylation of IV synthesized the 6-hydroxymethylidene derivative (XV). 6-Chloro- ,-hydroseleno-, and-anilinomethylidenemackinazoline thiones (XVI-XIX) were also synthesized. The antimicrobial activity of the synthesized compounds against S. aureus, E. coli, Bacillus cereus, Candida albicans, and Pseudomonas aeruginosa was studied.