Sodium Hydroxide → 3-(3-(4-methoxybenzyl)-6,7,8,9-tetrahydro-3H-pyrazolo[3,4-c][2,7]naphthyridine-7-carboxamido)benzoic acid

Participants

Reaction Steps

To a solution of ethyl 3-(3-(4-methoxybenzyl)-6,7,8,9-tetrahydro-3H-pyrazolo[3,4-c][2,7]naphthyridine-7-carboxamido)benzoate (0.162 g, 0.33 mmol) in methanol (5 mL) was added aqueous NaOH (0.13 g in 3 mL H2O, 3.3 mmol). The reaction was stirred at room temperature for 16 hours. On completion of the reaction the solvent was removed and the resulting aqueous solution was acidified to pH<2 using 2N HCl. A solid precipitated out, which was filtered, washed with water and dried to give the desired product, 3-(3-(4-methoxybenzyl)-6,7,8,9-tetrahydro-3H-pyrazolo[3,4-c][2,7]naphthyridine-7-carboxamido)benzoic acid (0.136 g, 90%) as a pale yellow solid. M.p.>136° C.; 1H NMR (400 MHz, DMSO-d6) δ12.95 (s, 1H), 8.93 (s, 1H), 8.41 (s, 1H), 8.19 (s, 1H), 8.10 (m, 1H), 7.78 (m, 1H), 7.53 (m, 1H), 7.36 (dd, J1=J2=8.4 Hz, 1H), 7.18 (m, 2H), 6.84 (m, 2H), 4.86 (m, s, 2H), 3.85 (t, J=6.0 Hz, 2H), 3.68 (s, 3H), 3.50 (m, 2H), 3.16 (t, J=6.0 Hz, 2H); LCMS [M+H]: 458.

Provenance & Evidence