[Synthesis]
To a DMF solution of 6-[2-(tert-butoxycarbonyl)hydrazinyl]nicotinic acid (0.57 g, 2.26 mmol) and butanediimide (0.27 g, 2.26 mmol) was added DCC (0.47 g, 2.26 mmol), and the reaction mixture gradually became turbid. After 1 hour of reaction, stirring was continued for 16 hours. After completion of the reaction, the mixture was concentrated to dryness and the residue was purified by silica gel column chromatography using ethyl acetate as eluent to afford the white solid product 2,5-dioxopyrrolidin-1-yl 6-(2-(tert-butoxycarbonyl)-hydrazino)nicotinic acid ester (0.66 g, 84% yield). Melting point: 174°C. IR (ATR, cm^-1): 3321, 2979, 1729, 1594, 1365, 1240, 1198, 1068, 974, 641. 1H NMR (DMSO-d6): δ 9.46 (s, 1H), 9.20 (s, 1H), 8.76 (d, 1H, J = 2.1Hz), 8.11 (d, 1H, J = 8.1Hz), 6.67 (d, 1H, J = 9Hz), 2.88 (s, 4H), 1.44 (s, 9H).13C NMR (DMSO-d6): δ 172.8, 170.5, 160.9, 155.4, 151.8, 110.0, 79.6, 28.0, 25.5.MS ( ESI+): m/z 351.00 [M + H]+. HRMS (ESI+): m/z [M + H]+ Calculated value for C15H19N4O6 is 351.1305, measured value is 351.1299. |