Novel 1,2,3-triazole 5a–q and isoxazole tagged 6a–i and 7a–g 2H-Chromene derivatives were prepared and screened for cytotoxic activity and promising compounds 5f, 5g, 5l, 5q have been identified.
A ...series of novel 2-(1,2,3-triazolylmethoxy) 5a–q and isoxazole tagged 6a–g 2H-Chromene derivatives were prepared starting from salicylaldehyde and ethyl-4,4,4-trifluoroacetoacetate via cyclization to form ethyl 2-hydroxy-2-(trifluoromethyl)-2H-Chromene-3-carboxylate 3. Compound 3 on reaction with propargyl bromide resulted compound 4 and was independently reacted with aryl/alkyl azides and aryl aldoximes obtained 2-(1,2,3-triazolylmethoxy) and isoxazole tagged 2H-Chromene derivatives 5a–q, 6a–i, respectively. Compounds 6 were further hydrolysed to acid derivatives 7a–g. All the products 5a–q, 6a–i, 7a–g were screened for cytotoxic activity against four human cancer cell lines and among all the compounds, 5f, 5g, 5l, 5q showed promising activity at <20μM concentration.
Novel 2-alkyl triazole-3-alkyl substituted quinoline derivatives 5a–o were prepared in series of steps and screened for antimicrobial and cytotoxic activity. The promising compounds in each case have ...been identified.
The propargyl alcohol on reaction with alkylazides under Sharpless conditions through click chemistry concept gave exclusively 1,4-disubstituted triazoles 2. The compounds 2 were oxidized to aldehydes 3 followed by reaction with aniline resulted Schiff’s bases 4. The compounds 4 was further reacted with various aldehydes having α-hydrogen using molecular iodine as a catalyst and obtained 2-alkyl triazole-3-alkyl substituted quinoline derivatives 5. All the final compounds were screened against four human cancer cell lines (THP-1, Colo205, U937 & HeLa) and promising compounds have been identified.
A series of novel N-alkyl dihydro pyrido quinoxaline derivatives were synthesized using Gould–Jacobs reaction and evaluated their antimalarial activity in vitro against chloroquine sensitive (3D7) ...and drug resistant (Dd2) strains of Plasmodium falciparum. Among the compounds tested, 10 compounds were more potent than their structural standard analog ciprofloxacin, including 2 derivatives 5e and 5h, which showed 3.3–7.4 times more potency than ciprofloxacin against both the parasite strains. The results are encouraging and a lead molecule may emerge which is useful alone or in combination therapy.
A series of novel (28) pyrido quinoxaline derivatives were synthesized and evaluated for antimalarial activity against the human malaria parasite Plasmodium falciparum. Some of the derivatives were more potent than ciprofloxacin, including the compound 5h shown below. Display omitted
•A convenient method to synthesize pyrido quinoxaline derivatives from quinoxaline-6-amine by Gould–Jacobs reaction.•Assessment of novel pyrido quinoxaline molecules for antimalarial activity.•Identified 10 compounds with more potency than ciprofloxacin.•Compounds 5e and 5h seem to be attractive candidates for optimization to achieve better potency.•All the potent compounds showed similar activity against both chloroquine sensitive and resistant strains.
Alky, aryl, and heteroaryl amines were found to react efficiently with formic acid under Lewis acid catalysis giving
N-formyl derivatives in high yields. A study of ZnCl
2-catalyzed N-formylation of ...a variety of amines using formic acid as formylating agent is described.
2-Substituted-5,7-dimethyl pyrido2,3-
dpyrimidin-4(1
H)-ones (
8) were synthesized by oxidation of 2-substituted-5,7-dimethyl dihydropyrido2,3-
dpyrimidin-4(1
H)-ones (
7) which were in turn prepared ...from 2-amino-4,6-dimethyl nicotinamide (
5) and substituted aryl aldehydes (
6). 2-Amino-4,6-dimethyl nicotinamide (
5) was prepared from ethyl cyanoacetate (
1) via malonamamidine hydrochloride (
3). The compounds were characterized by IR, NMR, MS and elemental analyses. Compounds
7 and
8 were screened for antibacterial activity against Gram positive and Gram negative bacteria. Dehydrogenated compounds (
8) showed less antibacterial activity than the compounds
7. Among all the test compounds screened for antibacterial activity
7c (1.25
μg/ml) showed greater activity. All the synthesized compounds were found inactive when screened for antifungal activity at the concentration of 200
μg/ml.
2-Substituted-5,7-dimethyl pyrido2,3-
dpyrimidin-4(1
H)-ones (
8) were synthesized by oxidation of 2-substituted-5,7-dimethyl dihydropyrido2,3-
dpyrimidin-4(1
H)-ones (
7) which were in turn prepared from 2-amino-4,6-dimethyl nicotinamide (
5) and substituted aromatic aldehydes (
6). 2-Amino-4,6-dimethyl nicotinamide (
5) was prepared from ethyl cyanoacetate via malonamamidine hydrochloride. Compounds
7 and
8 were screened for antibacterial activity against Gram positive and Gram negative bacteria. Dehydrogenated compounds (
8) showed less antibacterial activity than the compounds
7. Among all the test compounds screened for antibacterial activity
7c (1.25
μg/ml) showed greater activity.
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A series of novel substituted 4‐trifluoromethyl‐pyridin‐2‐yl hydrazide derivatives 5 and 7‐trifluoromethyl‐1,2,4‐triazolo4,3‐apyridine derivatives 6 were synthesized through a facile method in single ...step from 2‐hydrazino‐pyridine derivatives 4 and their reaction with aliphatic/aromatic acids in the presence of POCl3 and PCl5. In each reaction, an intermediate 5 and product 6 were formed in definite proportion except in 5a, 5d, and 6e and were independent of reaction time and temperature.
Organic Preparations and Procedures International An Efficient Multi-component Synthesis of 6-Amino-3-methyl-4-Aryl-2,4- dihydropyrano2,3-cPyrazole-5-carbonitriles
A series of novel 7,8 and 1,8 imidazo fused quinolone carboxamides are synthesized and evaluated against antibacterial activity. 1,8 Imidazo fused quinolones exhibit moderate antibacterial activity. ...Molecular modeling studies were carried out to optimize the pharmacophore.
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A facile and an efficient protocol has been developed for the synthesis of novel 1,2,3‐triazole substituted 4H‐chromene derivatives 4 in single pot by multicomponent reaction of 1,3‐cyclohexanedione, ...malononitrile and 1‐substituted 1,2,3‐triazole‐5‐aldehyde using potassium carbonate as catalyst.
An elegant synthetic strategy was adopted for the preparation of N‐triazolo methyl substituted fluoroquinolones 4 and screened for their antimicrobial activity. The synthetic methodology starts from ...N‐propargylation of ethyl 7‐chloro‐6‐fluoro‐4‐hydroxyquinoline‐3‐carboxylate (1) followed by reaction with azides through click reaction under Sharpless conditions furnished triazole substituted quinolone ester 3. The latter quinolone esters were reacted with various secondary amines to furnish the corresponding quinolone derivatives 4. Alternatively, quinolone carboxylic derivatives 7a, 7b, 7c, 7d were prepared in two steps from triazole tagged quinolone ester. All the final products were screened against various bacterial and fungal strains. Compounds 4a, 4b, 4c and 4k showed moderate antibacterial activity, and 4f showed promising activity against fungal strains.
