Derivational, Structural, and Biological Studies of Some New Pyrazolyl, Isoxazolyl, Pyrimidinyl, Pyridazinyl, and Pyridopyridazinyl from 4‐Substituted Antipyrine

Abstract

(1,5‐Dimethyl‐3‐oxo‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐4‐yl)carbono‐hydrazonoyl dicyanide was used as a key intermediate for the synthesis of novel pyrazole, isoxazole, pyrimidine, and pyridazine derivatives. The newly synthesized compounds were characterized by elemental analyses and spectral data (IR, 1H‐NMR, 13C‐NMR, and mass spectra). The compounds were tested for their in vitro antibacterial activity against Gram‐positive bacteria as (Staphylococcus aureus and Bacillus subtilis) and Gram‐negative bacteria (Pseudomonas aeruginosa and Escherichia coli). The investigated compounds were tested against two strains of fungi Botrytis fabae and Fusarium oxysporum using diffusion agar technique. The biological results showed clearly that most of the synthesized compounds revealed mild to moderate activity against the used microorganisms.

Recent Development of Pyrimidine‐Containing Antimicrobial Agents

“…Furthermore, Fadda et al [23] synthesized diaminopyrimidine derivatives 26(E) and 27(E) ( Figure 5) by introducing an imidazole to pyrimidine structure, which showed antimicrobial activity equivalent to that of reference drug ampicillin against S. aureus, B. subtilis, P. aeruginosa and E. coli. It's worth noting that compound 26 with pyrimidone had higher activity against Gram-positive bacteria and compound 27 with pyrimidinethione was more suitable for inhibiting Gram-negative bacteria and fungi than the others.…”

“…Furthermore, Fadda et al . synthesized diaminopyrimidine derivatives 26 (E) and 27 (E) (Figure ) by introducing an imidazole to pyrimidine structure, which showed antimicrobial activity equivalent to that of reference drug ampicillin against S. aureus , B. subtilis , P. aeruginosa and E. coli .…”

Facile synthesis of multi‐functional 1,3,4‐thiadiazine derivatives bearing phthalazine, pyridazine, and pyrido‐pyridazine moieties

“…Pyridazine derivatives have diverse biological activities including antihistaminic, analgesic, and anti‐inflammatory . The pyrido‐pyridazine ring is very attractive for many pharmaceutical industries because of the variety of their biological applications . Molecules bearing the 1,3,4‐thiadiazine core have also received great attention because of their extensive therapeutic activities .…”

“…[5][6][7][8][9][10][11][12] The pyrido-pyridazine ring is very attractive for many pharmaceutical industries because of the variety of their biological applications. [13][14][15][16] Molecules bearing the 1,3,4-thiadiazine core have also received great attention because of their extensive therapeutic activities. [17] The most widely employed methods for the construction of this group of compounds use thiohydrazides and α-halocarbonyl compounds such as α-haloketones, α-haloaldehydes, or alkylbromoacetates.…”

“…A series of novel, multifunctional 1,3,4-thiadiazine derivatives bearing phthalazines, pyridazines and pyrido-pyridazines (9)(10)(11)(12)(13) have been synthesized via the multicomponent reaction of (3-(2-bromo-2-[2-chloropyrimidin-4-yl]acetyl)-2-chlorophenyl)-2,6-dichloro benzene-sulfonamide with thiocarbohydrazide and various anhydrides. The reactions were performed by refluxing the components in mixed ethanol/acetic acid to afford the corresponding products in good to excellent yields.…”