Paliperidone Tetradehydro Impurity → Paliperidone

Reaction equation

[F:1][C:2]1[CH:31]=[CH:30][C:5]2[C:6]([CH:9]3[CH2:14][CH2:13][N:12]([CH2:15][CH2:16][C:17]4[C:22](=[O:23])[N:21]5[CH:24]=[CH:25][CH:26]=[C:27]([OH:28])[C:20]5=[N:19][C:18]=4[CH3:29])[CH2:11][CH2:10]3)=[N:7][O:8][C:4]=2[CH:3]=1>[Pt].[Pd].C(O)(=O)C>[CH3:29][C:18]1[N:19]=[C:20]2[N:21]([CH2:24][CH2:25][CH2:26][CH:27]2[OH:28])[C:22](=[O:23])[C:17]=1[CH2:16][CH2:15][N:12]1[CH2:13][CH2:14][CH:9]([C:6]2[C:5]3[CH:30]=[CH:31][C:2]([F:1])=[CH:3][C:4]=3[O:8][N:7]=2)[CH2:10][CH2:11]1

Participants

Procedure

In the step-b, the pyridine ring of 3-[2-[4-(6-fluoro-1,2-benzisoxazol-3-yl)piperidin-1-yl]ethyl]-9-hydroxy-2-methyl-4H-pyrido-[1,2-a]pyrimidin-4-one, compound of formula-11, is reduced by a suitable reducing agent as defined earlier. Good yields were obtained on hydrogenation using palladium or platinum catalyst in acidic conditions. In the preferred embodiment the reaction was performed by hydrogenation using palladium catalyst in presence of acetic acid to provide pure paliperidone.