Piperidine → N-{[2-(2,6-dioxo(3-piperidyl))-1,3-dioxoisoindolin-4-yl]methyl}piperidylcarboxamide

Participants

Reaction Steps

Diisopropylethylamine (0.88 g, 6.79 mmol) was added to a stirred suspension of 4-(aminomethyl)-2-(2,6-dioxo(3-piperidyl))isoindoline-1,3-dione hydrochloride (1.0 g, 3.09 mmol) in acetonitrile (50 mL). After stirring for 20 min, the mixture was slowly added to a stirred solution of triphosgene (0.34 g, 1.14 mmol) in acetonitrile (15 mL) over 30 min. After a further 10 min of stirring, a solution of piperidine (0.26 g, 3.09 mmol) and diisopropylethylamine (0.48 g, 3.71 mmol) in acetonitrile (10 mL) was added in one portion. The mixture was stirred at room temperature for 17 hours. The mixture was concentrated and the residue was dissolved in methylene chloride (80 mL). The methylene chloride solution was washed with 10% KHSO4 (30 mL), H2O (2×30 mL), brine (30 mL) and dried (MgSO4). Solvent was removed and the residue was purified by chromatography (CH2Cl2:CH3OH 97.5:2.5) to give N-{[2-(2,6-dioxo(3-piperidyl))-1,3-dioxoisoindolin-4- yl]methyl}piperidylcarboxamide (0.66 g, 53%) as a white solid: mp 156–158° C.; 1H NMR (DMSO-d6) δ 11.14 (s, 1H), 7.86–7.75 (m, 2H), 7.69 (d, J=7.4 Hz, 1H), 7.12 (t, J=5.6 Hz, 1H), 5.18–5.11 (dd, J=5.3 and 12.5 Hz, 1H), 4.69 (d, J=5.5 Hz, 2H), 3.42–3.32 (m, 4H), 2.96–2.83 (m, 1H), 2.63–2.50 (m, 2H), 2.08–2.03 (m, 1H), 1.54–1.44 (m, 6H); 13C NMR (DMSO-d6) δ 172.74, 169.83, 167.60, 157.26, 141.46, 134.58, 132.82, 131.38, 126.74, 121.43, 48.82, 44.37, 30.93, 25.37, 24.12, 21.98; Anal. Calcd. For C20H22N4O5+0.22 H2O: C, 59.70; H, 5.62; N, 13.92. Found: C, 60.14; H, 5.59; N, 13.47.

Provenance & Evidence