Hydrochloric Acid → HCID 178479602, compound

Participants

Reaction Conditions

Reaction Steps

To a sealed tube containing a solution of (S)-7-(quinuclidin-3-yl)-2-((2-(trimethylsilyl)ethoxy)methyl)-7,8-dihydropyrazolo[3,4,5-de]isoquinolin-6(2H)-one (0.71 g, 1.73 mmol) from Step D above in dioxane (10 mL) was added 6N HCl (20 mL). The reaction mixture was flushed with argon, sealed and heated to 115° C. for 30 min, cooled to ambient temperature and concentrated under reduced pressure. The residue was preabsorbed on silica gel and purified first by column chromatography (5 to 20% 6:3:1 dichloromethane/methanol/concentrated ammonium hydroxide in 9:1 dichloromethane/methanol) and subsequently by reverse phase semi-preparative HPLC (isocratic, 10% acetonitrile in water—both eluents contained 0.05% trifluoroacetic acid as modifier). The solvents were removed in vacuo and the desired product trifluoroacetate salt was dissolved in a solution 1.25 N HCl in methanol (4×5 mL) and the solvent removed (4×) to exchange the trifluoroacetate salt to the hydrochloride salt form. Recrystallization of the desired product hydrochloride salt from ethanol (10 mL), followed by lyophilization from acetonitrile/water (1:5, 6 mL) afforded (S)-7-(quinuclidin-3-yl)-7,8-dihydropyrazolo[3,4,5-de]isoquinolin-6(2H)-one, hydrochloride salt (85.9 mg, 18%) as an amorphous white solid: 1H NMR (500 MHz, d6-DMSO) δ 13.15 (s, 1H), 10.15 (s, 1H), 7.65 (d, J=8.5 Hz, 1H), 7.75 (dd, J=7.0, 7.0 Hz, 1H), 7.45 (d, J=7.0 Hz, 1H), 5.32-5.14 (m, 2H), 4.79 (t, J=9.5 Hz, 1H), 3.78-3.47 (m, 4H), 3.32-3.16 (m, 3H), 2.26-2.18 (m, 1H), 2.03-1.80 (m, 3H), MS (ESI+) m/z 283 (M+H)+; HPLC 98.8% (AUC), tR 7.29 min.

Provenance & Evidence