[NH:1]1[CH2:6][CH2:5][CH:4]([CH:7]2[CH2:12][CH2:11][NH:10][CH2:9][CH2:8]2)[CH2:3][CH2:2]1.[CH3:13][C:14]([O:17][C:18](ON=C(C1C=CC=CC=1)C#N)=[O:19])([CH3:16])[CH3:15].C([O-])([O-])=O.[K+].[K+]>C1COCC1.C(Cl)(Cl)Cl>[N:1]1([C:18]([O:17][C:14]([CH3:16])([CH3:15])[CH3:13])=[O:19])[CH2:6][CH2:5][CH:4]([CH:7]2[CH2:12][CH2:11][NH:10][CH2:9][CH2:8]2)[CH2:3][CH2:2]1
To 4,4′-bipiperidine (5.48 g, 32.6 mmol) in THF (160 mL) and CHCl3 (160 mL) was added BOC-On (4.01 g) in THF (90 mL) dropwise over a 8 h period. The reaction was then concentrated and purified by flash chromatography. The residue was taken up in 1M KHSO4 (250 mL) and washed with diethyl ether (three times). K2CO3 (38.0 g, 275 mmol) was added to the aqueous layer which was subsequently extracted with CHCl3 (3×), dried (MgSO4) and concentrated to provide the title compound of step A (1.98 g, 7.40 mmol, 45%). 1H NMR (400 MHz, CDCl3) δ ppm 1.06-1.18 (m, 5H), 1.42 (s, 9H), 1.58-1.69 (m, 6H), 2.50-2.61 (m, 4H), 3.06 (d, J=12.1 Hz, 2H), 4.08 (br. s., 2H).
Wird geladen…
