反应详情

A mixture of crude Pyridazine-3-carboximidamide hydrochloride, 30-id, (4.2 g, 34.4 mmol), diethyl ethoxymethylenemalonate (6.5 mL, 34.4 mmol) and sodium methoxide (1.85 g, 41.3 mmol) in MeOH (100 mL) was refluxed overnight. The reaction mixture was added with KOH (3.8 g, 68.8 mmol) and refluxed for 4 h. The reaction was concentrated. The residue was dissolved with water (30 mL) and extracted with EtOAc. The aqueous layer was adjusted to pH=2 by addition of concentrated aq. HCl. The solids was filtered and rinsed with water and hexane to afford the title compound, 30-ie, (3 g, 40%). 1H NMR (300 MHz, CD3OD) δ14.7 (s, 1H), 9.50 (dd, J=1.6, 5.0 Hz), 8.57 (s, 1H), 8.51 (dd, J=1.6, 8.4 Hz, 1H), 8.01 (dd, J=5.0, 8.4 Hz, 1H), 3.44 (s, 1H). LC-MS: (M+H)+ 219.

1. temperaturewas refluxed overnight
2. temperaturerefluxed for 4 h
3. concentrationThe reaction was concentrated
4. dissolutionThe residue was dissolved with water (30 mL)
5. extractionextracted with EtOAc
6. additionThe aqueous layer was adjusted to pH=2 by addition of concentrated aq. HCl
7. filtrationThe solids was filtered
8. washrinsed with water and hexane