Hydrochloric Acid → 5-(4-Chloro-phenyl)-6-[4-(3-methyl-[1,2,4]oxadiazol-5-yl)-phenyl]-1-phenyl-1,5-dihydro-pyrazolo[3,4-d]pyrimidin-4-one

Participants

Reaction Steps

A solution of 4-[5-(4-chloro-phenyl)-4-oxo-1-phenyl-4,5-dihydro-1H-pyrazolo[3,4-d]pyrimidin-6-yl]-benzoic acid methyl ester (50 mg, 0.11 mmol) in dioxane is added NaOH (1N, 400 μL, 0.4 mmol) and stirred at room temperature for 14 h. The mixture is then neutralized by adding HCl (1N, 400 μL, 0.4 mmol) and concentrated. The resulted residue is treated with SOCl2 (1 mL) at room temperature for 1 h and excess SOCl2 is removed under vacuum. The residue is dissolved in CH2Cl2 and added N-hydroxy-acetamidine (12 mg, 0.16 mmol) followed by Et3N (17 mg, 0.16 mmol). After stirring at room temperature for 1 h, the mixture is treated with water (2 mL) and extracted with EtOAc (3×2 mL). The organic layers are combined and concentrated, the residue is dissolved in EtOH (4 mL), NaOAc (40 mg) is added and the mixture is heated to 80° C. for 5 h. After cooling down to room temperature, the solvent is removed and the residue is purified by preparative LC/MS to provide the titled compound 5-(4-chloro-phenyl)-6-[4-(3-methyl-[1,2,4]oxadiazol-5-yl)-phenyl]-1-phenyl-1,5-dihydro-pyrazolo[3,4-d]pyrimidin-4-one. 1H NMR (CDCl3) δ(ppm) 8.35(s, 1H), 8.12(d, 2H), 8.01(d, 2H), 7.48-7.54 (m, 4H), 7.37 (t, 1H), 7.32(d, 2H), 7.10(d, 2H), 2.47(s, 3H); HPLC-MS calculated for C26H17ClN6O2 (M+H+): 481.1. Found: 481.1.

Provenance & Evidence