Nhlanhla Gracious Shabalala, Nagaraju Kerru, S. Maddila
Aug 1, 2020
Citations
1
Influential Citations
12
Citations
Journal
Chemical Data Collections
Abstract
Abstract We report an efficient one-pot method for bis-3-methyl-1-phenyl-1H-pyrazol-5-ol derivatives under ultrasound irradiation using β-keto ester, phenylhydrazine, and benzaldehydes as reactants in aqueous ethanol. Excellent yields (92–99%) obtained at RT in 5 to 8 min. Products were characterised by FT-IR, HRMS, 1H and 13C NMR analysis. We described the crystal structure of 2‑methoxy-phenyl compound 4a. Compound (C28H27N4O3) crystallised in the orthorhombic system with space group Pna21, and along the b-axis of the unit, cell contained four asymmetric molecules. The unit cell parameters were a = 17.2578(2) A, b = 17.26256(2) A, c = 7.76970(10) A, α = β = γ = 90°, V = 2315.11(5) A3, Z = 4. The crystal structure was stabilised by an intramolecular hydrogen bond (O—H…O). π-π intermolecular interactions existed between the phenyl and pyrazolone rings with 3.54 A separation. The prominent features are catalyst-free, green protocol, simple work-up, rapid synthesis, excellent yields, and no column chromatography.