Compound 10: 4-Benzoyl-2-(4-methoxybenzyl)-1,2-dihydro-3H-pyrazol-3-one

Created: 2022-11-05 08:27

Last modified: 2024-06-25 08:45

License: Creative Commons: Public Domain Dedication 1.0

Funding: (none given)

Description

4-Benzoyl-2-(4-methoxybenzyl)-1,2-dihydro-3H-pyrazol-3-one (10): Bz-Cl (2.753 g, 2.270 mL, 19.59 mmol, 1.00 equiv) was added with stirring to Ca(OH)2 (726.0 mg, 9.793 mmol, 2.00 equiv) and pyrazolone 9 (4.000g, 19.59 mmol, 1.00 equiv) in 1,4-dioxane (40 mL). After heating at 100 °C for 4 h, the mixture was cooled to room temperature and acidified with aqueous HCl (1 M) to pH = 1 – 2. The mixture was stirred for 1 , the precipitate was collected by filtration and air dried and subsequently dried in vacuo. Additional material was obtained through addition of H2O to the filtrate. The precipitate was collected by filtration, air dried and subsequently dried in vacuo. Pyrazolone 10 (4.134 g, 13.41 mmol, 68%) was obtained as a yellow solid, essentially pure by its 1H NMR spectrum. Analytically pure samples were obtained by recrystallization from EtOH. Rf (hexanes : EtOAc 7 : 3) = 0.05. 1H-NMR (400 MHz, CDCl3): δ (ppm) = 7.94 – 7.86 (m, 2H), 7.78 (s, 1H), 7.60 (dd, J = 8.5, 6.0 Hz, 1H), 7.52 (t, J = 7.5 Hz, 2H), 7.32 (d, J = 8.2 Hz, 2H), 6.91 – 6.85 (m, 2H), 6.14 (s, 2H), 5.14 (s, 2H), 3.79 (s, 3H). 1H-NMR (400 MHz, CD3OD): δ (ppm) = 7.85 (d, J = 7.5 Hz, 2H), 7.77 (s, 1H), 7.60 (t, J = 7.3 Hz, 1H), 7.51 (t, J = 7.5 Hz, 2H), 7.24 (d, J = 8.2 Hz, 2H), 6.87 (d, J = 8.2 Hz, 2H), 4.91 (s, 2H), 3.75 (s, 3H). 13C{1H}-NMR (101 MHz, CDCl3): δ (ppm) = 190.3, 159.8, 159.6, 139.1, 137.4, 132.9, 129.8, 128.9, 128.5, 127.7, 114.3, 102.5, 55.4, 49.9. 13C{1H}-NMR (101 MHz, CD3OD): δ (ppm) = 191.3, 161.0, 159.2, 140.8, 139.4, 133.6, 130.3, 129.7, 129.6, 129.2, 115.1, 104.5, 55.7, 50.2. IR (Diamond-ATR, neat) νmax (cm-1) = 2924, 1623, 1611, 1597, 1528, 1511, 1444, 1304, 1236, 1216, 1178, 1030, 1021, 901, 785, 723, 700. HRMS (ES-ToF) m/z: [M + H]+ calc. for (C18H17N2O3)+: 309.1234, found: 309.1247. m.p.: 95 – 97 °C (EtOH) (lit.[4] m.p. 98 – 99 °C). Anal. Calcd for C18H16N2O3: C, 70.12; H, 5.23; N; 9.09. Found: C, 68.83; H, 4.95; N, 8.56 The analytic data were in good agreement with literature values.[4]

Member of collection / collaboration

DOI	Description
10.14469/hpc/10386	Syntheses and Characterization of Main Group, Transition Metal, Lanthanide and Actinide Complexes of Bidentate Acylpyrazolone Ligands

Members

DOI	Description
10.14469/hpc/11830	NMR Data for Compound 10.
10.14469/hpc/11838	IR Data for Compound 10.

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