Ethyl Acetate → 5-(4-chloro-phenyl)-6-(2,4-dichlorophenyl)-1-phenyl-1H-pyrazolo[3,4-b]pyridin-4-ylamine

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Reaction Steps

A solution of 2-(4-chloro-phenyl)-1-(2,4-dichloro-phenyl)-ethanone (300 mg, 0.99 mmol) in dichloroethane (3 mL) is stirred at room temperature while TiCl4 (311 mg, 1.64 mmol) is added dropwise. After the addition, the mixture is stirred at room temperature for 5 minutes and a solution of 5-amino-1-phenyl-1H-pyrazole-4-carbonitrile (150 mg, 0.815 mmol) in dichloroethane (3 mL) is added dropwise. After the addition, the mixture is heated to 125° C. for 5 hours. After cooling, the mixture is poured into a mixture of ice cold saturated aqueous NaHCOs solution (30 mL) and EtOAc (30 mL). The resultant precipitate is filtered through celite and washed with EtOAc (2×10 mL). The filtrate is extracted by EtOAc (3×15 mL). The organic layers are combined and washed with brine and dried (MgSO4). After filtering off the drying agent, the filtrate is concentrated and purified by column chromatography (silica gel, 0%˜40% EtOAc/hexane) to provide the titled compound 5-(4-chloro-phenyl)-6-(2,4-dichloro-phenyl)-1-phenyl-1H-pyrazolo[3,4-b]pyridin-4-ylamine as light yellow solid:

Provenance & Evidence