Synthesis of 2-pyrazolines from pyridine based chalcone by conventional and microwave techniques: Their comparison and antimicrobial studies

3-(3,4-Dimethoxyphenyl)-5-(2-fluorophenyl)-1-phenyl-4,5-dihydro-1H-pyrazole

“…These absorptions are due to the asymmetrical and symmetrical vibrations of aromatic C-H bonds, respectively, and they were confirmed by the appearance of aromatic proton signals around δ (ppm) 7.52-6.80 and aromatic carbon signals around δ 160.73-108. 16 in the 1 H and 13 C NMR spectrum, respectively.…”

“…Other researchers have also reported one-pot synthesis of pyrazolines from various starting materials and methods such as from 3-butynol and substituted phenylhydrazine under reflux condition [12], from substituted acetophenone, benzaldehyde, and phenylhydrazine under reflux condition [13,14] and through the formal [4 + 1] annulation reaction of 3-bromooxindoles and in situ-derived 1,2-diaza-1,3-dienes by stirring at room temperature [15]. In addition, it has also been reported that the one-pot synthesis of pyrazolines can be performed by reacting pyridine based chalcone and hydrazine hydrate under 300 W microwave irradiation [16]; by reacting substituted chalcone, hydrazine hydrate, and acetic anhydride under 550 W microwave irradiation [17]; and by reacting substituted pyrazole, formaldehyde, and β-diketone under 300 W microwave irradiation [18]. However, the use of a sealed-vessel reactor in one-pot synthesis of pyrazoline from substituted benzaldehyde, acetophenone, and phenylhydrazine has not been reported previously.…”

Synthesis, crystal structure and Hirshfeld surface analysis of 4-[3-(4-hydroxyphenyl)-4,5-dihydro-1H-pyrazol-5-yl]-2-methoxyphenol monohydrate

“…Heterocyclic compounds including pyrazolines can be synthesized from chalcone derivatives. Many compounds containing pyrazolines show different biological activities and are known to act as anticancer (Johnson et al, 2007;Gomha et al, 2017), antimicrobial (Patel et al, 2016), antitubercular (Taj et al, 2011), anti-inflammatory (Malhotra et al, 2010), anticonvulsant (Siddiqui et al, 2009), antiamoebic (Bhat et al, 2009), antioxidant (Srinivasan et al, 2007), antiviral (Gomha et al, 2016), antibacterial (Kumar et al, 2008) and antinociceptive (Kaplancikli et al, 2009) agents.…”

“…Pyrazoline derivatives have been synthesized by condensation of chalcones with hydrazine derivatives using conventional synthesis (Shahare et al, 2009;Sridhar et al, 2012) and microwave-assisted synthesis (Kumar et al, 2008;Patel et al, 2016).…”

Microwave-Assisted Stereoselective Heterocyclization to Novel Ring d-fused Arylpyrazolines in the Estrone Series

“…Although the incorporation of a ring-condensed pyrazoline moiety—most frequently by the reactions of steroidal enones with hydrazine derivatives—is relatively common in the androstane [18,19,20,26,29] and cholestane series [28,30], surprisingly, only a few examples are to be found in the literature for the construction of such heterocycles on estrone-based molecules [21], which may also possess valuable bioactivities. Since the use of MW irradiation can advantageously affect the outcome of various organic syntheses leading to different heterocycles both in product yield and chemoselectivity [31], this technique is often applied for the efficient access to both steroidal and non-steroidal pyrazolines [29,32,33,34]. Considering the high optical purity of chiral steroids, heterocyclization reactions often proceed in a stereoselective manner to afford one of the possible isomers mainly or exclusively, making these reactions more attractive both from a chemical and pharmacological points of view.…”