4-Methylphthalimide → 5-Methyl-2,3-dihydro-1H-isoindol-1-one

Step 1 A mixture of 5-methylisoindoline-1,3-dione (5.00 g, 31.0 mmol) and tin shavings (8.84 g, 74.5 mmol) in acetic acid (30 mL) and concentrated hydrochloric acid (15 mL) was heated at reflux for 3 h. The hot solution was filtered and the residual tin shavings were washed with acetic acid. The filtrate was concentrated and the residue was diluted with DCM (200 mL), and washed with water (20 mL) and brine (20 mL), dried and concentrated. The precipitate which formed during the concentration was collected by filtration and washed with DCM (5 mL) and dried under vacuum to give 5-methylisoindolin-1-one (2.3 g, 50%). 1H NMR (400 MHz, chloroform-d) δ 7.70 (1H, d, J=7.77 Hz), 7.43 (1H, s), 7.35 (1H, d, J=7.77 Hz), 4.46 (2H, s), 2.48 (3H, s). Mass spectrum m/z 148.0 (M+H)+.

1. temperaturewas heated
2. temperatureat reflux for 3 h
3. filtrationThe hot solution was filtered
4. washthe residual tin shavings were washed with acetic acid
5. concentrationThe filtrate was concentrated
6. additionthe residue was diluted with DCM (200 mL)
7. washwashed with water (20 mL) and brine (20 mL)
8. customdried
9. concentrationconcentrated
10. customThe precipitate which formed during the concentration
11. filtrationwas collected by filtration
12. washwashed with DCM (5 mL)
13. customdried under vacuum

ORD record

ord-f0fc7b752281430c91914d48b1f782e6

Source dataset

uspto-grants-2011_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08084620B2