Piperazine → HCID 68843659, compound

Participants

Reaction Steps

Piperazine (258 mg; 3 mmole) was added to a stirred suspension of 2-acetamido-6-(3,4-dimethoxyphenyl)-4-(1,2,4-triazolyl)pyrido[3,2-d]pyrimidine (586 mg; 1.5 mmole) in dioxane (50 ml). The mixture was stirred at room temperature for 24 hours and the volatiles were removed under reduced pressure, yielding 2-acetamido-4-(N-piperazinyl)-6-(3,4-dimethoxyphenyl)-pyrido[3,2-d]pyrimidine as a crude residue. The latter was dissolved in DMF and m-tolyl isocyanate (0.66 ml, 5 mmole) was added. After 18 hours at room temperature, the solvent was removed and the residue was suspended in a mixture of CH2Cl2 (20 ml) and sodium ethoxide 0.2 N (20 ml). The suspension was stirred during 16 hours and neutralized with 5-6 N HCl in isopropyl alcohol. The crude residue was purified by silica gel column chromatography, the mobile phase consisting of a CH3OH/CH2Cl2 mixture in a ratio gradually ranging from 2:98 to 5:95, thus resulting in the pure title compound (350 mg, yield 43%) which was characterized by its mass spectrum as follows: MS (m/z): 542 ([M+H]+, 100).

Provenance & Evidence