Facile Regioselective Synthesis of Novel bis‐Thiazole Derivatives and Their Antimicrobial Activity

Abstract

The design and synthesis of several new bis-thiazoles 4a-h serving as bis-drugs in comparison with mono-heterocyclic analogs are described. These bis-drugs present superior medicinal and pharmacological activities against both gram-negative (Pseudomonas aeruginosa and Escherichia coli) and gram-positive (Micrococcus luteus and Bacillus subtilis) bacteria, which are in general more sensitive to compounds with higher hydrophobicity. Compounds with higher hydrophobicity (4d and 4h) exhibited some activity against the gram-negative bacteria.

One pot multicomponent synthesis of Novel Bis‐N‐(1,2,3‐ triazolylacetyl) as Potent Antioxidant and Antibacterial Agents

“…In support of our previous interest in developing efficient two directional synthesis and designing new molecules with biological activities [16][17][18][19][20][21][22] here, a semi-three-component "Huisgen" reaction for the synthesis of bis-1,2,3-triazoles 5a-i is reported. The viability of obtaining bis-1,2,3-triazoles 5a-i by 1,3-cycloaddition of bis-azides 3a-i and diethyl acetylenedicarboxylate 4 in the presence of CuCl 2 under solvent-free conditions was explored.…”

“…The reason for selecting bis-bromo ketones 1a-h scaffolds as starting materials to build up the core moieties is due to their similarity to acetanisole unit and was prepared according to the literature. [21] The acetanisole unit is used as the pharmaceutical sector and food flavoring and presented in the structure of bis-ketoazides 3a-i. In the other efforts" 3a-i were prepared from reaction 1a-i with NaN 3 in THF/H 2 O (1:1), refluxing for 3h.…”

Practical one-pot synthesis of semicarbazone derivatives via semicarbazide, and evaluation of their antibacterial activity

“…It is clear that vibrational frequency of the C=O group increases on going from cis-cis to cis-trans and then trans-trans, with the exceptional trans-trans form of 1f due to the presence of NH_OC H-bonding. [33]. Compound 1f showed activity against P. aeruginosa at a concentration of 512 lg/ mL and S. aureus at a concentration of 128 lg/mL, while other compounds showed no activity against bacterial strains.…”

“…Continuing our studies of the synthesis of novel compounds bearing heteroatoms [31][32][33][34][35][36] here, synthesis of a new series of 2-(aryl or alkyl)-N-phenylhydrazine-1-carboxamide 1a-j via one-pot reaction is completed. The products 1a-j were obtained through the reaction of anthracene carbaldehyde 4g or cyclic aliphatics 4a-f, or aromatic ketones 4h-j with hydrazine hydrate and phenyl isocyante 5 in MeOH under reflux condition (Scheme 2).…”

Synthesis and Evaluation of Novel [1,2,4]Triazolo[1,5‐c]quinazoline Derivatives as Antibacterial Agents

“…The new triazolo‐quinazolines 5a – 5g were evaluated for their in vitro antibacterial activity against three Gram‐positive and two Gram‐negative bacteria [ Staphylococcus aureus ( S. aureus ) ATCC 25923, Bacillus cereus ( B. cereus ) ATCC 11778, and Micrococcus luteus ( M. luteus ) ATCC 9341] and Gram‐negative bacteria [ Escherichia coli ( E. coli ) ATCC 25922 and Pseudomonas aeruginosa ( P. aeruginosa ) ATCC 27853] using the zone inhibition method . Dimethyl sulfoxide (DMSO) was used as a negative control and showed no activity against aforementioned bacterial strains.…”