prepare | 1, refluxing the solution of 10 a1(4g,26mmol)(Molekula), cyclopropylamine 10 a2(4.5mL,64.9mmol)(Avra) and N,N-diisopropylethylamine (8.9mL,54mmol) in EtOH(15mL) for 3h. The reaction mixture was cooled to 0°C and the solids in the suspension were collected by filtration. The obtained solids were washed with cold EtOH to give the intermediate 10 a3. 2. Stir the solution of intermediate 10 a3(3.8g,21mmol) and Pd/C 10%(760mg) in EtOH(32mL) for 2h in a hydrogen atmosphere at 50psi. The catalyst was filtered by diatomite. The filtrate was evaporated under reduced pressure to give the intermediate 10 a4. 3. Carbonyl diimidazole (2.2g,13.4mmol) was added to the solution of intermediate 10 a4(2g,13.4mmol) in ACN(40mL) at 0 ℃. Stir the mixture at room temperature for 1h. The precipitate was collected by filtration to obtain the intermediate 3a1-3, I. e. 1-cyclopropyl-1, 3-dihydroimidazolo [4,5-C] pyridin-2-one. |