p-Toluenesulfonic acid → 5,6-bis-(4-chloro-phenyl)-1-phenyl-1H-pyrazolo[3,4-b]pyrazine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 1,2-bis-(4-chloro-phenyl)-ethane-1,2-dione from Step A (˜20 mg), 2-phenyl-2H-pyrazole-3,4-diamine from Step B (25 mg) and p-TSA in MeOH (1 mL) is heated to 80° C. for 2 h. After cooling down to room temperature, the mixture is treated with saturated aqueous NaHCO3 solution (3 mL) and extracted with EtOAc (3×2 mL). The organic layers are combined and concentrated. The residue is purified by Preparative LC/MS to provide the title compound 5,6-bis-(4-chloro-phenyl)-1-phenyl-1H-pyrazolo[3,4-b]pyrazine. 1H NMR (CDCl3) δ(ppm) 8.51(s, 1H), 8.34 (d, 2H), 7.56(t, 2H), 7.46(d, 2H), 7.32˜7.43 (m, 7H); HPLC-MS calculated for C23H14Cl2N4 (M+H+): 417.1. Found: 417.1.

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