反应详情

A mixture of (1RS,3RS,5RS)-2-benzyl-3-[2-(1,3-dioxan-2-yl)ethyl]-2,7-diazabicyclo[3.3.0]octane-7-carboxylic acid, ethyl ester (0.3081 g, 0.793 mmol) and 4-(imidazol-1-yl)phenylhydrazine, dihydrochloride (0.2055 g, 0.832 mmol) in 4% H2SO4 (aq) (10 mL) was heated at reflux under argon for 20 h whilst stirring magnetically. After cooling, the reaction mixture was made basic with 50% NaOH solution and extracted with EtOAc (4×25 mL). The combined organic extracts were dried (K2CO3) and evaporated in vacuo. The residue was purified by flash chromatography (silica gel, 2-4% MeOH/CH2Cl2) to give 0.1625 g (44%) of the title compound as a yellow gum. δH (250 MHz, CDCl3) 1.23-1.26 (3H, m), 1.56-1.68 (1H, m), 1.92 (1H, m), 2.56 (1H, m), 2.79 (1H, m), 3.14 (1H, dd), 3.17-3.78 (7H, m), 4.07-4.13 (3H, m), 7.10-7.34 (11H, m), 7.74 (1H, s), 8.24 (1H, br s). m/e (ES+) 470 (M+H)+.

1. temperaturewas heated
2. temperatureat reflux under argon for 20 h
3. temperatureAfter cooling
4. extractionextracted with EtOAc (4×25 mL)
5. dry with materialThe combined organic extracts were dried (K2CO3)
6. customevaporated in vacuo
7. customThe residue was purified by flash chromatography (silica gel, 2-4% MeOH/CH2Cl2)