Synthesis
b) Synthesis of 5-(3-methoxyphenyl)-2H-pyrazol-3-amine
To a solution of 3-(3-methoxyphenyl)-3-oxopropanenitrile (8.96 mmol) in anhydrous ethanol (20 mL) was added hydrazine monohydrate (0.52 mL, 15 mmol), and the reaction mixture was heated and refluxed for 18 hours. After completion of the reaction, the mixture was cooled to room temperature and concentrated under reduced pressure to remove the solvent. The crude product was washed with ether and filtered to give 1.4 g of the title compound in 83% yield.
Product Characterization:
Molecular formula: C10H11N3O
Theoretical mass-to-charge ratio (m/z): 189
Measured mass-to-charge ratio (m/z): [M + H+] = 190
Liquid chromatography retention time (LC Rt): 1.13 min (5 min method)
1H-NMR (400 MHz, MeOH-d4) δ: 3.82 (3H, s, OCH3); 5.93 (1H, s, CH); 6.86-6.88 (1H, m, ArH); 7.19-7.31 (3H, m, ArH).
References
[1] Patent: WO2008/87529, 2008, A1. Location in patent: Page/Page column 105
[2] Patent: WO2010/9290, 2010, A1. Location in patent: Page/Page column 136
[3] Patent: WO2007/98826, 2007, A2. Location in patent: Page/Page column 71
[4] Beilstein Journal of Organic Chemistry, 2018, vol. 14, p. 122 - 1228
[5] Bioorganic and Medicinal Chemistry, 2006, vol. 14, # 22, p. 7501 - 7511
