Hydrochloric Acid → 1-phenyl-6,7,8,9-tetrahydro-3H-pyrazolo[3,4-c][2,7]naphthyridin-7-ium chloride

Participants

Reaction Steps

To a solution of tert-butyl 1-phenyl-8,9-dihydro-3H-pyrazolo[3,4-c][2,7]naphthyridine-7(6H)-carboxylate (0.21 g, 0.60 mmol) in dichloromethane (5 mL) was added 4 M solution of HCl gas in 1,4-dioxane (1.5 mL, 6.0 mmol). The reaction was shaken at room temperature for 16 hours. A yellow solid precipitated out in the reaction mixture, which was filtered to give the pure desired product, 1-phenyl-6,7,8,9-tetrahydro-3H-pyrazolo[3,4-c][2,7]naphthyridin-7-ium chloride (0.184 g, 95%) as a yellow solid; M.p.=265° C. decomposition; 400 MHz 1H NMR (DMSO-d6) δ: 13.91 (s, 1H), 9.39 (s, 2H), 8.43 (s, 1H), 7.62-7.46 (m, 5H), 4.44-3.38 (m, 2H), 3.38-3.2 (m, 2H), 3.01 (t, J=6.4 Hz, 2H); LCMS [M+H]: 251.

Provenance & Evidence