反应详情

温度

-78 °C

Diisopropylamine (1.54 g, 15 mmol) was dissolved in THF (50 mL) and then the mixture was cooled to −78° C. n-Butyl lithium (6.1 mL, 2.5 M in hexane) was added dropwise at −78° C. After addition, the reaction mixture was stirred for 30 min at −78° C. Ethyl 1-benzyl-4-(N-phenylacetamido)piperidine-4-carboxylate (2.9 g, 7.6 mmol) was added dropwise at −78° C. The mixture was continued to stir for 1 h at −78° C. The reaction was quenched by dropwise addition of water (10 mL) at −78° C. and then allowed to warm to room temperature. The organic layer was separated. The aqueous phase was acidified to pH 6-7 with acetic acid and extracted with EtOAc (3×20 mL). The combined organics were washed with brine, dried over Na2SO4 and evaporated under vacuum to give crude product as a solid, which was washed with ether to give 8-benzyl-1-phenyl-1,8-diazaspiro[4.5]decane-2,4-dione. 1H NMR (300 MHz, MeOD) δ 7.12-7.47 (m, 15H), 4.04 (s, 2H), 3.65-3.66 (m, 2H), 3.51-3.57 (m, 1H), 3.02-3.06 (m, 2H), 2.66-2.73 (m, 2H), 1.93-2.00 (m, 5H), 1.82-1.87 (m, 1H).

1. additionwas added dropwise at −78° C
2. additionAfter addition
3. stirringto stir for 1 h at −78° C
4. customThe reaction was quenched by dropwise addition of water (10 mL) at −78° C.
5. temperatureto warm to room temperature
6. customThe organic layer was separated
7. extractionextracted with EtOAc (3×20 mL)
8. washThe combined organics were washed with brine
9. dry with materialdried over Na2SO4
10. customevaporated under vacuum
11. customto give crude product as a solid, which
12. washwas washed with ether