[C:1](=[NH:14])([C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.N[CH:16]1[CH2:21][CH2:20][CH2:19][NH:18][C:17]1=[O:22]>ClCCCl>[C:1](=[N:14][CH:16]1[CH2:21][CH2:20][CH2:19][NH:18][C:17]1=[O:22])([C:8]1[CH:9]=[CH:10][CH:11]=[CH:12][CH:13]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1Benzophenone imine (3 mL, 17.87 mmol) was added to a solution of 3-aminopiperidin-2-one [CAS 1892-22-4] (2 g, 17.52 mmol) and molecular sieves in DCE (50 mL) under nitrogen and the reaction was warmed to 80° C. for 18 hours. The solvent was evaporated and the residue applied to a 100 g SNAP column, eluting with 50 to 100% EtOAc/ihexane to afford 3-(benzhydrylideneamino)-piperidin-2-one (D21) (3.84 g, 13.796 mmol, 78.7% yield) as a colourless solid.
Wird geladen…