反应详情

A solution of 1,3-cycloheptadione (2 g, mmol) was heated to reflux for 1 hour with dimethylforamide dimethylacetal (15 mL). The reaction mixture was concentrated and triturated with ether to yield 1.8 g of 2-dimethylaminomethylene-cycloheptane-1,3-dione. A solution of 2-dimethylaminomethylene-cycloheptane-1,3-dione (0.52 g, 2.9 mmol) and t-butylhydrazine hydrochloride (0.44 g, 3.5 mmol) in n-butanol (25 mL) and 0.3 mL of acetic acid was heated to reflux for 16 hours. The solvents were evaporated and the residue was chromatographed, eluting with 30% ethyl acetate/hexane to yield the title compound: 1H NMR (300 MHz, CDCl3) δ 7.85 (s, 1 H), 3.17 (m, 2 H), 2.68 (m, 2 H), 1.98 (m, 2 H), 1.89 (m, 2H) 1.68 (s, 9 H); MS (DCI/NH3) m/z 207 (M+H)+.

1. temperatureto reflux for 16 hours
2. customThe solvents were evaporated
3. customthe residue was chromatographed
4. washeluting with 30% ethyl acetate/hexane