反应详情

To a solution of 1-tert-butyl 4-ethyl 3-oxopiperidine-1,4-dicarboxylate (2.00 g, 7.39 mmol) in EtOH (37 mL) was added formamidine hydrochloride (910 mg, 11.08 mmol) followed by NaOEt (6.89 mL, 2.68 M in EtOH) dropwise. The mixture was then heated to reflux overnight. The mixture was concentrated in vacuo and then dissolved in a minimum amount of water. The pH was adjusted to pH 7 with 1 N HCl. The aqueous layer was then saturated with solid NaCl and extracted with a combination of EtOAc and DCM. The combined organic extracts were dried over Na2SO4, filtered and concentrated in vacuo. Chromatography on SiO2 eluting with IPA/EtOAc afforded the desired product as a white solid (993 mg, 53%). MS (ESI) mass calcd. C12H12N3O3, 251.13. m/z found 252.1 [M+H]+. 1H NMR (500 MHz, CDCl3): 8.05 (s, 1H), 4.42 (s, 2H), 3.69-3.61 (m, 2H), 2.63 (s, 2H), 1.49 (s, 9H).

1. temperatureThe mixture was then heated
2. temperatureto reflux overnight
3. concentrationThe mixture was concentrated in vacuo
4. dissolutiondissolved in a minimum amount of water
5. extractionsaturated with solid NaCl and extracted with a combination of EtOAc and DCM
6. dry with materialThe combined organic extracts were dried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated in vacuo