To a cooled solution (0-5° C.) of 6-(4-aminopiperidin-1-yl)nicotinamide hydrochloride (293 mg, 1 mmol) in 5 ml DMF was added DIPEA (645 mg, 2.2 mmol) and 1,1′-carbonyldiimidazole (170 mg, 1.05 mmol). After stirring for 1 h, 1-isopropylpiperazine (154 mg, 1.2 mmol) was added and the resulting mixture was warmed to room temperature for 16 h. The crude mixture was filtered through Celite and the filtrate was purified by preparative HPLC to give title compound (30 mg, 8%) as an off-white solid. [1HNMR (400 MHz, DMSO-d6) δ 8.60 (d, 1H), 7.94 (m, 1H), 7.73 (s, 1H), 7.10 (s, 1H), 6.86 (d, 1H), 6.21 (d, 1H), 4.37 (d, 2H), 3.65 (m, 1H), 3.23 (t, 4H), 2.94 (t, 2H) 2.62 (m, 1H), 2.34 (t, 4H), 1.78 (d, 2H), 1.36 (m, 2H), 0.96 (d, 6H); LCMS RtB=1.53 min, [M+H]+=375.2].
