反应详情

A mixture of 2-methyl-7-oxo-4,5,6,7-tetrahydro-benzothiazole-6-carbaldehyde (200 mg, 1 mmol), meta-nitro-phenyl guanidine nitrate (248 mg, 1), NaOH (41 mg, 1 mmol) and 2-methoxyethanol (2 mL) was heated under reflux for 16 h. The reaction mixture was concentrated under vacuum. Flash column chromatography (20% EtOAc:hexane) gave the title compound as a yellow solid (18 mg, 5%): mp 227-228° C. Anal. RP-HPLC: tR 21.9 min (0-60% MeCN, purity 100%). 1H-NMR (DMSO-d6): δ 10.00 (s, 1H, NH), 8.89 (t, 1H, J 2.3, Ph-H), 8.30 (s, 1H, Py-H), 7.92 (ddd, 1H, J 8.3, 2.3, 0.7, Ph-H), 7.66 (ddd, 1H, J 8.3, 2.3, 0.7, Ph-H), 7.44 (t, 1H, J 8.3, Ph-H), 2.90 (m, 4H, CH2—CH2), 2.66 (s, 3H, CH3). 13C-NMR (DMSO-d6): δ 169.16, 159.27, 158.42, 156.05, 155.39, 148.04, 142.02, 129.57, 127.56, 124.22, 117.13, 115.16, 111.91, 24.56, 23.06, 19.48. MS (ESI−): m/z 337.94 (M−H)+.

1. temperaturewas heated
2. temperatureunder reflux for 16 h
3. concentrationThe reaction mixture was concentrated under vacuum