Hydrochloric Acid → 1-(3-benzenesulfonylpropyl)-2-butyl-2H-pyrazolo[3,4-c]quinolin-4-amine

Participants

Reaction Steps

Hydrochloric acid (0.98 mL, 3.90 mmol) in ethanol was added dropwise to a solution of 4-(2-aminophenyl)-5-(3-benzenesulfonylpropyl)-1-butyl-1H-pyrazole-3-carbonitrile (550 mg, 1.30 mmol) in 10 mL of ethanol. The resultant solution was stirred for 2 hours, concentrated under reduced pressure, and diluted with water. The pH of the mixture was adjusted to 8-9 by slow addition of solid sodium carbonate. The aqueous layer was extracted with several portions of dichloromethane. The combined organic layers were washed with brine, dried over magnesium sulfate, filtered, and concentrated under reduced pressure to afford a pale yellow solid. The material was purified via flash column chromatography on silica gel (eluting with a 97:3 mixture of dichloromethane/methanol) to afford 350 mg of 1-(3-benzenesulfonylpropyl)-2-butyl-2H-pyrazolo[3,4-c]quinolin-4-amine as a white crystalline solid, mp 206-207° C. 1H NMR (300 MHz, CDCl3) δ 7.87 (d, J=6.9 Hz, 2H), 7.77 (dd, J=1.2, 8.1 Hz, 1H), 7.69 (dd, J=0.9, 8.1 Hz, 1H), 7.63 (m, 1H), 7.53 (m, 2H), 5.37 (br s, 2H), 4.35 (app t, J=7.2 Hz, 2H), 3.45 (m, 2H), 3.22 (t, J=7.1 Hz, 2H), 2.23 (m, 2H), 1.94 (m, 2H), 1.40 (qd, J=7.2, 14.6 Hz, 2H), 0.98 (t. J=7.3 Hz, 3H); MS (APCI) m/z 423 (M+H+); Anal. calcd for C23H26N4O2S: C, 65.38; H, 6.20; N, 13.26. Found: C, 65.40; H, 6.01; N, 13.26.

Provenance & Evidence