Synthesis, biological evaluation and docking studies of (4-aryl-3-methyl-4,5-dihydropyrazolo[3,4-c]pyrazol-1(3aH)-yl)(3-hydroxyquinoxalin-2-yl)methanones

862-866An efficient synthesis of (4-aryl-3-methyl-4,5-dihydropyrazolo[3,4-c]pyrazol-1(3aH)-yl)(3-hydroxyquinoxalin-2-yl) methanones is described via reactions of ethyl acetoacetate with 3-hydroxyquinoxaline-2-carbohydrazide. The structures of the compounds prepared have been determined by spectral analyses

Synthesis, biological evaluation and docking studies of (4-aryl-3-methyl-4,5-dihydropyrazolo[3,4-c]pyrazol-1(3aH)-yl)(3-hydroxyquinoxalin-2-yl)methanones

An efficient synthesis of (4-aryl-3-methyl-4,5-dihydropyrazolo[3,4-c]pyrazol-1(3aH)-yl)(3-hydroxyquinoxalin-2-yl) methanones is described via reactions of ethyl acetoacetate with 3-hydroxyquinoxaline-2-carbohydrazide. The structures of the compounds prepared have been determined by spectral analyses

DFT Analysis, ADME, antibacterial activity and molecular docking studies of 2-(3-aryl-1,2,4-oxadiazol-5-yl)-n-phenylacetamide derivatives

Quantum computational study based on density functional theory (DFT/B3LYP) using basis set 6-311G (d,p) a number of global and local reactivity descriptors have been computed to predict the reactivity and the reactive sites on the 2-(3-aryl-1,2,4-oxadiazol-5-yl)-n-phenylacetamideoxadiazole derivatives. The molecular geometry and the electronic properties such as frontier molecular orbital (HOMO and LUMO), ionization potential (I) and electron affinity (A) are investigated to get a better insight of the molecular properties. Molecular electrostatic potential (MEP) for all compounds were determined to check their electrophilic or nucleophilic reactivity. The in silico pharmacokinetics showed that nearly all derivatives obeyed Lipinski rule of 5 with low toxicity and metabolic stability. The antibacterial activity was carried out against B. subtilis, S. aureus, P.aeruginosa and E. coli, displaying considerable inhibition. MurE ligases, (PDB: 7b6k) participating in the intracellular steps of bacterial peptidoglycan biosynthesis, are taken as targets for molecular docking studies using Flare GUI software. The docking outcome revealed that these 1,2,4-oxadiazole analogues have highest LF rank score in the range -12.9 to -6.0 which shows that they act as potent antibacterial agents

<span style="font-size:13.0pt;mso-bidi-font-size: 8.0pt;font-family:"Times New Roman","serif";mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language:AR-SA" lang="EN-GB">An efficient synthesis of 1-(quinoxalin-6-yl)-1<i style="mso-bidi-font-style:normal">H</i>-1,2,3-triazole-4-carboxylic acid</span>

761-762<span style="font-size:11.0pt;mso-bidi-font-size: 10.0pt;font-family:" times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";="" letter-spacing:-.1pt;mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:ar-sa"="" lang="EN-GB">Efficient syntheses of quinoxalines from the reaction of glyoxal and o-phenylenediamine and formation of 1,2,3-triazole on the quinoxalines base moity are described.</span

A facile synthesis of 3-hydroxy-<i style="mso-bidi-font-style:normal">N</i>-(4-oxo-2-arylthiazolidin-3-yl)quinoxaline-2-carboxamides and <i style="mso-bidi-font-style:normal">N</i>-(3-chloro-2-oxo-4-arylazetidin-1-yl)-3-hydroxyquinoxaline-2-carboxamides

1222-1225<i style="mso-bidi-font-style: normal">o-Phenylenediamine reacts with diethylbromo malonate to form ethyl-1,2,3,4-tetrahydro-3-oxoquinoxaline-2-carboxylate <b style="mso-bidi-font-weight: normal">2, which reacts with hydrazinehydrate to form 3-hydroxy-quinoxaline-2-carbohydrazide 3. Compound 3 on condensation with different aromatic aldehydes gives N'-arylidene-3-hydroxyquinoxaline-2-carbohydrazides 4 which is cyclised with chloroacetyl chloride and thioglycolic acid to obtain N-(3-chloro-2-oxo-4-arylazetidin-1-yl)-3-hydroxyquinoxaline-2-carboxamides 5 and 3-hydroxy-N-(4-oxo-2-phenylthiazolidin-3-yl)quinoxaline-2-carboxamides 6 respectively.<b style="mso-bidi-font-weight: normal"> The structures of these compounds are confirmed by 1H NMR and LC-MS data

Synthesis and antibacterial activity of some new quinaxaline-benzohydrazides

207-212Quinoxalines have been found to exhibit various biological activities such as antibacterial, antifungal, anti-tubercular, anxiolytic, anticancer, antioxidant, anti-inflammatory, anti-HIV, antihelmintic and anticonvulsant. The present study aims towards synthesis, characterization and determination of antimicrobial susceptibility testing of various novel quinoxaline derivatives. <span style="mso-bidi-font-weight: bold">The quinoxaline-benzohydrazides 6a-m have been obtained by the condensation of quinoxaline-2-carboxaldehyde 4 with various benzohydrazides 5a-m in ethanol at reflux temperature. All the newly synthesized quinoxaline-benzohydrazide derivatives have been characterized by 1H NMR, IR and mass spectroscopic analysis. The synthesized quinoxaline-benzohydrazides 6a-m have been screened for antibacterial activity. Most of the compounds show significant antibacterial activity. </span

Synthesis and antimicrobial activity of 1-alkyl and aryl-3-(2-methyl-1,8-naphthyridin-3-yl)ureas

1271-12731,8-naphthyridine derivatives have attracted considerable attention because they are the chief constituent of many compounds which have been isolated from natural sources, with various biological activities. Nalidixic acid, for example, possesses strong antibacterial activity and used mainly for the treatment of urinary tract infections with gram negative pathogens and Gemifloxacin has antimicrobial and antibacterial activities. It is known that (E)- and (Z)-o-(diethylamino)ethyl oximes of 1,8-naphthyridine series have the potential for use as local anesthetics and 1-(2-fluorobenzyl)-3-(2-tolyl)-1,8-naphthyridin-2(1H)-one is used for the treatment of memory disorders, in particular, Alzheimer’s disease. In recent years, research on derivatives of 1,8-naphthyridine has been intensive because these compounds show a wide range of biological activities. 2-Methyl-1,8-naphthyridine-3-carbonylazide has been synthesized from ethyl-2-methyl-1,8-naphthyridine-3-carboxylate following two different procedures. The azide on heating with aliphatic and aromatic primaryamines in xylene underwent Curtius rearrangement to furnish the title compounds. They have been screened for their antimicrobial activity

Synthesis and antimicrobial activity of 2-cyclopropyl [1,8]naphthyridine-3-carboxylic acid (4-phenyl-2-thioxo-thiazol-3-yl)-amides, [1,3,5]triazine, [1,3,4]thiadiazole-2-thiol, [1,2,4]triazole-3-thiol and coumarin derivatives

440-4472-Cyclopropyl-[1,8]naphthyridine-3-carboxylic acid ethyl ester 1 reacts with 99% hydrazine hydrate, to yield 2-cyclopropyl-[1,8]naphthyridine-3-carboxylic acid hydrazide 2, which further reacts with carbon disulphide in the presence of potassium hydroxide solution to yield compound 3. Compound 3 reacts with 99% hydrazine hydrate to offer 4-amino-5-(2-cyclopropyl-[1,8]naphthyridin-3-yl)-4<i style="mso-bidi-font-style: normal">H-[1,2,4]triazole-3-thiol 4. Compound 4 is<b style="mso-bidi-font-weight: normal"> converted to 5 by reaction with phenacyl bromides. On other hand compound <b style="mso-bidi-font-weight: normal">4 on treatment with oxalyl chloride in the presence of triethyl amine provides 6. Compound 3 on treatment with acetic acid in water gives compound 7. On the other hand compound 3 on treatment with phenacyl bromides provides compound 8. Compound 1 reacts with guanidine hydrochloride to yield compound 9 which reacts with aromatic nitriles to offer compound <b style="mso-bidi-font-weight: normal">10

<span style="font-size:11.0pt;font-family: "Times New Roman","serif";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language: HI;mso-bidi-font-weight:bold" lang="EN-GB">Synthesis, characterization and antimicrobial evaluation of <span style="font-size:11.0pt;font-family:"Times New Roman","serif"; mso-fareast-font-family:"Times New Roman";mso-bidi-font-family:Mangal; mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language:HI" lang="EN-GB">(<i style="mso-bidi-font-style:normal">E</i>)- 4-(substitutedphenyl)-<i style="mso-bidi-font-style:normal">N</i>'-(1-phenylethylidene)cyclohexane carbohydrazide derivatives</span></span>

718-723<span style="font-size:11.0pt;font-family: " times="" new="" roman","serif";mso-fareast-font-family:minionpro-regular;mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">Encouraged by the various biological activities associated with hydrazone derivatives, the present paper describes the synthesis, characterization and antimicrobial evaluation of (<i style="mso-bidi-font-style: normal">E)-4-(substituted phenyl)-N'-(1-phenylethylidene) cyclohexanecarbohydrazide derivatives 4a-k from commercially available <span style="font-size:11.0pt; font-family:" times="" new="" roman","serif";mso-fareast-font-family:advot863180fb;="" mso-bidi-font-family:mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:hi"="" lang="EN-GB">4-(4-chlorophenyl)cyclohexanecarboxylic acid. The hydrazide-hydrazone derivatives 4a-k have been synthesized via the nucleophilic addition-elimination reaction of substituted acetophenones a-k with 4-(4-chlorophenyl)cyclohexanecarbohydrazide 3<span style="mso-bidi-font-weight: bold">. <span style="font-size:11.0pt;font-family: " times="" new="" roman","serif";mso-fareast-font-family:advot863180fb;mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">The structures of the synthesized compounds are confirmed by 1H NMR, IR and mass spectral data. <span style="font-size:11.0pt; font-family:" times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:hi"="" lang="EN-GB">All the synthesized 4-(4-chlorophenyl)cyclohexane carbohydrazide derivatives 4a-k have been evaluated for their in vitro antibacterial activity against Staphylococcus aureus and Staphylococcus pyogenes <span style="mso-bidi-font-style: italic">(gram positive bacteria) and Escherichia coli and Pseudomonas aeruginosa (gram negative bacteria). The antibacterial screening results reveal that compounds 4f-j exhibit good antibacterial activity with zone of inhibition 21-25 mm while the compounds 4a-c show moderate antibacterial activity with zone of inhibition 16-20 mm whereas the compounds 4d, <b style="mso-bidi-font-weight: normal">4e and 4k show nil activity.</span