1-Methylpiperazine → 5-(4-Chloro-phenyl)-6-(2,4-dichloro-phenyl)-1-[4-(4-methyl-piperazine-1-carbonyl)-phenyl]-1,5-dihydro-pyrazolo[3,4-d]pyrimidin-4-one

Participants

Reaction Steps

4-[5-(4-Chloro-phenyl)-6-(2,4-dichloro-phenyl)-4-oxo-4,5-dihydro-pyrazolo[3,4-d]pyrimidin-1-yl]-benzoic acid (54.1 mg, 0.106 mmol) is dissolved in 1 mL of thionyl chloride and stirred for 1 h at reflux. The thionyl chloride is then removed under a stream of dry nitrogen and the resulting solid is dissolved in 2 mL of dry dichloromethane. N-methylpiperazine (500 mg, 5.00 mmol) is then added to the solution and the reaction mixture is stirred for 2 h. After the volatiles are evaporated, the resulting residue is dissolved in 1 M NaOH and extracted with ethyl acetate. The crude product is purified by column chromatography. 1H NMR (CDCl3, 400 MHz) δ 8.36(s, 1H), 8.28 (d, 2H), 7.57 (d, 2H), 7.36-7.29 (m, 3H), 7.23-7.16 (m, 2H), 7.03 (m, 1H), 3.97 (m, 3H), 3.48 (m, 2H), 2.83 (m, 6H). HPLC-MS calculated for C29H23Cl3N6O2 (M+H+) 593.1. Found: 593.1.

Provenance & Evidence