Ultrasound-mediated catalyst-free protocol for the synthesis of bis-3-methyl-1-phenyl-1H-pyrazol-5-ols in aqueous ethanol

Insights into 4,4′‐Arylmethylene‐Bis‐1H‐Pyrazol‐5‐Ols Scaffolds: Various Synthetic Routes and Their Applications

“…The main features of the above system are green protocol, catalyst-free, rapid synthesis,simple work-up, no column chromatography and high yields (Scheme 37). [108] Hasaninejad et al developed an environment friendly and suitable approach for the synthesis of (3) by the reaction of ( 5) with ( 6) and (1) in ethanol: water system in ultrasound irradiation. This protocol offered a number of an important advantages like less reaction time, high yields and easy workup procedure (Scheme 37).…”

Exploring the synthetic potential of a g-C3N4·SO3H ionic liquid catalyst for one-pot synthesis of 1,1-dihomoarylmethane scaffolds via Knoevenagel–Michael reaction

“…Yellow solid, yield: 98%, m.p. 189–191 °C, 26 1 H NMR (400 MHz, CDCl 3 ): δ 8.19 (s, 1H, OH), 7.56–7.54 (d, J = 9.0 Hz, 5H, Ar–H), 7.23–7.21 (s, 2H, Ar–H), 7.08 (t, J = 7.8 Hz, 2H, Ar–H), 6.70–6.65 (d, J = 19.3 Hz, 4H, Ar–H), 4.68 (s, 1H, CH), 3.74 (s, 3H, OCH 3 ), 2.12 (s, 6H, 2CH 3 ). 13 C NMR (101 MHz, DMSO-d6): δ 146.79, 146.65, 146.42, 135.12, 129.49, 129.02, 126.14, 121.27, 121.20, 121.04, 120.84, 118.13, 115.30, 112.62, 112.57, 56.17, 32.81, 12.14; ESI-MS ( m / z ): 482.20 [M + ].…”

“…Light yellow crystals, yield: 95%, m.p. 194–199 °C, 26 1 H NMR (400 MHz, CDCl 3 ): δ 7.63–7.61 (d, J = 9.1 Hz, 4H, Ar–H), 7.32–7.28 (dd, J = 10.5, 4.8 Hz, 4H, Ar–H), 7.15–7.11 (m, 2H, Ar–H), 6.49 (s, 2H, Ar–H), 4.72 (s, 1H, CH), 3.77–3.3.72 (d, J = 20.3 Hz, 9H, 3OCH 3 ), 2.16 (s, 6H, 2CH 3 ). 13 C NMR (101 MHz, DMSO-d6): δ 153.06, 153.03, 153.02, 139.13, 136.38, 129.70, 129.49, 121.29, 120.90, 105.31, 60.45, 56.30, 34.33, 26.86; ESI-MS ( m / z ): 526.22 [M + ].…”

“…[18][19][20][21][22][23][24][25] 1-Phenyl-3-methyl- 5-pyrazolone (edaravone) is used as a precursor for synthesizing various pyrazolone derivatives with several biological activities viz anti-inammatory, antimicrobial, and anticancer agents. 26,27 It has a wide range of applications in analytical chemistry, pharmaceuticals, dyes, pigments, colorants, chelating agents, and corrosion inhibition. 15,28,29 4-Hydroxycoumarin, also known as 4-coumarinol, is a precursor to the synthesis of several coumarin derivatives.…”

Ultrasound assisted synthesis of 5–7 membered heterocyclic rings in organic molecules

“…Maddila et al reported an atom economical method for the synthesis of 4 H ‐chromene derivatives ( 198a‐k, 200a‐k ) using one pot multicomponent approach through ultrasound irradiation under catalyst free conditions. Method is advantageous due to 100% carbon capture and yields more than 92% (Scheme 45) [86].…”