反应详情

To a solution of tert-butyl methyl(2-(6-(thiophene-2-carboximidamido)-2H-benzo[b][1,4]oxazin-4(3H)-yl)ethyl)carbamate (0.07 g, 0.168 mmol) in HPLC grade MeOH (10 mL) was added 3M hydrochloric acid (0.56 mL, 1.681 mmol). The resulting yellow solution was heated to reflux under an atmosphere of argon. After 60 minutes, the reaction was cooled to room temperature and concentrated. The residue was diluted with H2O (20 mL) and rinsed sequentially with CH2Cl2 (20 mL) and EtOAc (20 mL). The aqueous layer was concentrated and dried to yield the title compound 10 as a yellow solid (37 mg, 56.5%). 1H NMR (DMSO-d6) δ 11.37 (brs, 1H), 9.72 (brs, 1H), 9.23 (brs, 2H), 8.66 (brs, 1H), 8.21-8.08 (m, 2H), 7.37 (app t, 1H, J=4.4 Hz), 7.03 (s, 1H), 6.84 (d, 1H, J=8.3 Hz), 6.60 (d, 1H, J=7.3 Hz), 4.31-4.20 (m, 2H), 3.70-3.45 (m, 2H, merged with H2O peak), 3.40-3.34 (m, 2H), 3.18-3.02 (m, 2H), 2.60-2.50 (m, 3H); ESI-MS (m/z, %): 317 (MH+, free base, 100); ESI-HRMS calculated for C16H21N4OS (MH+, free base): 317.1430; observed: 317.1422.

1. temperatureThe resulting yellow solution was heated
2. temperatureto reflux under an atmosphere of argon
3. concentrationconcentrated
4. additionThe residue was diluted with H2O (20 mL)
5. washrinsed sequentially with CH2Cl2 (20 mL) and EtOAc (20 mL)
6. concentrationThe aqueous layer was concentrated
7. customdried