Chemotherapy of leishmaniasis part-VIII: Synthesis and bioevaluation of novel chalcones

Synthesis, Antibacterial and Antifungal Activity of Some New Pyrazoline and Pyrazole Derivatives

“…Its structure was confirmed by 1 H-NMR, 13 C-NMR spectra, and elemental analysis. On the other hand, treatment of the prepared hydrazine derivative 24 with ethyl acetoacetate in acetic acid afforded 1-(5H- [1,2,4]triazino [5,6-b]indol-3-yl)-3-methyl-1H-pyrazol-5(4H)-one (32) (Scheme 3). The proton NMR spectrum of this compound showed the CH 3 protons as a singlet at 1.80 ppm, and the CH 2 protons as a singlet at 2.43 ppm.…”

“…The proton NMR spectrum of this compound showed the CH 3 protons as a singlet at 1.80 ppm, and the CH 2 protons as a singlet at 2.43 ppm. 1-(5H- [1,2,4]Triazino [5,6-b]indol-3-yl)-3-methyl-4-(propan-2-ylidene)-1H-pyrazol-5(4H)-one (34) was prepared from the previous pyrazoline-5-one derivative 32 by its reaction with acetone (Scheme 3). The proton NMR spectrum showed two methyl protons as a singlet at 1.87 ppm.…”

“…Cyclization of quinoxaline-2,3(1H,4H)-dione (1''') with thiosemicarbazide afforded 5,10-dihydro- [1,2,4]triazino [5,6-b]quinoxaline-3-thiol (23) in good yield (Scheme 3). Its proton NMR spectrum showed two broad singlets, exchangeable with D 2 O, at 11.88 and 14.50 ppm, corresponding to the three NH protons, which confirm the structure of 23.…”

“…Chalcones have been recently the subject of great interest due to their interesting pharmacological activities, including antioxidant [1,2], antibacterial [3], antileishmanial [4], anticancer [5], antiangiogenic [6], anti-infective, anti-inflammatory [7], antifungal [8], anti-malarial [9], anti-tumor [10], anti-protozoal [11] and cytotoxic properties [12]. Many pyrazole derivatives are reported to have a broad spectrum of biological activities, such as anti-inflammatory [13], antifungal [14], antiviral [15], cytotoxic [12], A3 adenosine receptor antagonists [16], antioxidant [13], antihypertensive [17], tranquilizing, muscle relaxant, psychoanaleptic, hypnotic, ulcerogenic, antidepressant, antibacterial and analgesic effects [18].…”

“…New 2-pyrazoline derivatives 13-15 bearing benzenesulfonamide moieties were then synthesized by condensing the appropriate chalcones 2-4 with 4-hydrazinyl benzenesulfonamide hydrochloride. Ethyl [1,2,4] Condensation of 6,6-dimethyl-4-oxo-4,5,6,7-tetrahydro-1H-indole-2-carbaldehyde (1') with compound 24 or 25 afforded the corresponding Schiff's bases 36 and 37, respectively. Reaction of the Schiff's base 37 with benzoyl hydrazine or acetic anhydride afforded benzohydrazide derivative 39 and the cyclized compound 40, respectively.…”