Methanol → 6-(4-Acetyl-phenyl)-5-(4-chloro-phenyl)-1-phenyl-1,5-dihydro-pyrazolo[3,4-d]pyrimidin-4-one

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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 (450 mg, 0.98 mmol) in dioxane (6 mL) is added NaOH (2 N, 1.5 mL, 3 mmol) and stirred at room temperature for 14 h. The mixture is then concentrated and treated with SOCl2 (4 mL) at room temperature for 1 h. The excess SOCl2 is removed under vacuum and flushed with toluene (2×2 mL). The resulted residue is dissolved in CH2Cl2 (3 mL) and slowly dropped into a solution of freshly prepared Me2CuLi (2.0 mmol) in Et20 (4 mL) at −78° C. The mixture is kept at the same temperature for 1 h. when MeOH (1 mL) is added to quench the reaction. The mixture is then allowed to warm up to room temperature and treated with saturated aqueous NH4Cl solution (20 mL). After extraction with EtOAc(3×15 mL), the organic layers are combined, washed with brine and dried (MgSO4). After filtering off the drying agent, the solvent is removed under vacuum and the residue is purified by flash column chromatography (silica gel, 0%˜50% EtOAc/hexane) to provide the titled compound 6-(4-acetyl-phenyl)-5-(4-chloro-phenyl)-1-phenyl-1,5-dihydro-pyrazolo[3,4-d]pyrimidin-4-one. HPLC-MS calculated for C25H17ClN4O2 (M+H+): 441.1. Found: 441.1.

Provenance & Evidence