4-Methyl-1,3-isobenzofurandione → 3-(4-Methyl-1,3-dioxoisoindolin-2-yl)-2,6-dioxo-5-acetoxypiperidine
Reaction equation
[O:1]=[C:2]1[CH:7]([NH:8][C:9]([O:11]CC2C=CC=CC=2)=O)[CH2:6][CH:5]([O:19][C:20](=[O:22])[CH3:21])[C:4](=[O:23])[NH:3]1.C[C:25]1[CH:35]=[CH:34][CH:33]=[C:27]2[C:28](O[C:31](=O)[C:26]=12)=[O:29]>C(O)(=O)C.[Pd]>[CH3:31][C:26]1[CH:25]=[CH:35][CH:34]=[C:33]2[C:27]=1[C:28](=[O:29])[N:8]([CH:7]1[CH2:6][CH:5]([O:19][C:20](=[O:22])[CH3:21])[C:4](=[O:23])[NH:3][C:2]1=[O:1])[C:9]2=[O:11]Participants
5
Procedure
A mixture of 2,6-dioxo-3-benzyloxycarbonylamino-5-acetoxypiperidine (9 g, 28.2 mmol) (U. Teubert et al, Arch. Pharm. Pharm. Med. Chem. (1998) 7–12) and Pd/C (10%, 0.9 g) in acetic acid (90 mL) is shaken under hydrogen (50–60 psi) for 3 hours. The suspension is filtered through a pad of Celite and washed with acetic acid. To the filtrate is added 3-methylphthalic anhydride (4.56 g, 28.2 mmol) and this mixture is heated at reflux for 18 hours. The solvent is removed in vacuo to give 3-(4-methyl-1,3-dioxoisoindolin-2-yl)-2,6-dioxo-5-acetoxypiperidine which can be further purified by column chromatography.
Workup
- filtrationThe suspension is filtered through a pad of Celite
- washwashed with acetic acid
- temperaturethis mixture is heated
- temperatureat reflux for 18 hours
- customThe solvent is removed in vacuo
Sources & evidence
- ORD record
- ord-794f7db6c22b4df3adef3dbfcfb6b9be
- Source dataset
- uspto-grants-2006_02
- Patent number
- US07005438B2
Reaction notes
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