Synthesis and antioxidant activity evaluation of new hexahydropyrimido[5,4-c]quinoline-2,5-diones and 2-thioxohexahydropyrimido[5,4-c]quinoline-5-ones obtained by Biginelli reaction in two steps

Synthesis, characterization, antiamoebic activity and cytotoxicity of new pyrazolo[3, 4-d]pyrimidine-6-one derivatives

“…For methyl group of pyrazol ring, a singlet at 2.47-2.48 ppm was found in all the compounds (2a-2j), whereas for compounds (2e) and (2j), the appearance of singlet for methyl group was found in the range of 2.11-2.38 ppm. A singlet at 3.86 ppm for two OCH 3 protons was found in compound (2g).The structure of the compounds (2a-2j) was further supported by 13 C NMR spectra. The appearance of signals in the range of 161.5-162.8 ppm and 50.1-52.8 ppm due to C=O and methine carbon atom (pyrimidine nucleus) confirmed the formation of pyrazolo [3,4-d]pyrimidine-6-ones (2a-2j) (Figure 1).…”

“…The appearance of singlet at 2.16 ppm corresponds to the methyl group of pyrazolon nucleus also confirmed the formation of cyclized structure (1a). The structure of 5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one (1a) was further supported by 13 C NMR spectra. The appearance of signal at 170 ppm due to (C=O) group of desire pyrazolon nucleus confirmed the formation of 5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one.…”

“…All the compounds (2a-2j) were recrystallized from appropriate solvents and the yield was in the range of 36-48%. All the compounds were highly soluble in methanol and DMSO and were characterized by IR, 1 H and 13 C NMR, and Mass spectra. The purity of the compounds was confirmed by elemental analysis and data were found in accordance with ±0.3%.…”

Synthesis and biological evaluation of novel neoflavonoid derivatives as potential antidiabetic agents

“…All the synthesized compounds were evaluated for their antioxidant activities in the way of scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) 23 and hydroxyl radical. 24 Vitamin C was used as a reference compound in this assay. As shown in Table 4, most compounds of 4a-4p and 8a-8n demonstrated moderate to great scavenging activity, among which 8c, 8d and 8h-8n with several hydroxyl groups showed excellent activity in the both two aspects.…”

Synthesis and Antibacterial Evaluation of Tetrahydropyrimidine-5-carboxamide

“…For example, some of these compounds are very potent calcium channel blockers and act as antihypertensive, antiviral, antitumor and anti-inflammatory agents [1][2][3][4][5][6][7][8]. Previous studies on biological activity of dihydropyridines (DHPs) have revealed that dihydropyridines having carbamoyl moieties at 3 rd and 5 th positions showed significant antituberculosis activity [9].…”