反应详情

To a suspension of 5 g (0.032 mol) of N-cyclohexyl thiourea in 50 mL of ethanol at rt was added 5.38 g (0.0318 mol) of 1,1-dimethoxy-2-bromoethane. To the reaction mixture was then added 1.25 mL of 12N HCl and the reaction mixture was heated at reflux for 12 h. The reaction mixture was then concentrated to provide an orange-brown oil which was dissolved in 50 mL of dichloromethane. The organic solution was washed twice with 1N NaOH solution (50 mL) and then with H2O. The organic fraction was dried (Na2SO4), filtered and the filtrate was concentrated to give 5.95 g of off-white solid. The residue was purified by chromatography (silica, 0 to 5% EtOAc in cyclohexane) to give the title compound. 1H NMR (CDCl3) δ 6.45 (1H, d), 5.69 (1H, d), 4.20-4.10 (1H, m), 1.99-1.55 (6H, 3 sets of m).

1. temperaturethe reaction mixture was heated
2. temperatureat reflux for 12 h
3. concentrationThe reaction mixture was then concentrated
4. customto provide an orange-brown oil which
5. washThe organic solution was washed twice with 1N NaOH solution (50 mL)
6. dry with materialThe organic fraction was dried (Na2SO4)
7. filtrationfiltered
8. concentrationthe filtrate was concentrated