反应详情

温度

80 °C

To tert-butyl 4-[[benzyl-[2-oxo-2-(2-pyridyl)ethyl]amino]methyl]-4-hydroxy-piperidine-1-carboxylate (190 mg, 0.43 mmol) in benzene (11 mL) was added 4-methylbenzenesulfonic acid (99 mg, 0.52 mmol) and reaction mixture was heated at 80° C. for 30 minutes. The reaction mixture was cooled, diluted with ethyl acetate and washed sequentially with sat. NaHCO3 and brine solution. The organic layer was separated, dried over Na2SO4, filtered and concentrated in vacuo to give residue, which was purified using silica gel column chromatography using EtOAc/DCM (10-100%) as eluent to give tert-butyl 8-benzyl-10-(2-pyridyl)-11-oxa-3,8-diazaspiro[5.5]undec-9-ene-3-carboxylate (86 mg, 45%). ESI-MS m/z calc. 421.5. Found 422.2 (M+1)+; Retention time: 1.42 minutes (3 min run). 1H NMR (400 MHz, CDCl3) δ 8.40-8.34 (m, 1H), 7.56 (dd, J=4.0, 3.5 Hz, 1H), 7.37-7.27 (m, 6H), 7.07 (s, 1H), 6.92 (d, J=1.5 Hz, 1H), 4.22 (s, 2H), 3.99-3.76 (m, 2H), 3.17 (t, J=11.8 Hz, 2H), 2.78 (s, 2H), 1.83 (s, 2H), 1.44 (s, 9H), 1.40 (d, J=4.4 Hz, 2H).

1. temperatureThe reaction mixture was cooled
2. washwashed sequentially with sat. NaHCO3 and brine solution
3. customThe organic layer was separated
4. dry with materialdried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customto give residue, which
8. customwas purified