反应详情

A mixture of 2-benzyl-4-methyl-isoindole-1,3-dione (0.500 g, 2 mmol), tin (0.59 g, 5 mmol) and concentrated HCl (2 mL) in isopropanol (10 mL) was heated at reflux for 2.5 h. After this time, the reaction mixture was cooled to ambient temperature, the solids removed by filtration and the filtrate concentrated. The resulting material was dissolved in dichloromethane (20 mL) and the solution washed with brine (7 mL). The organic solution was separated, dried over anhydrous MgSO4, filtered, and concentrated to afford a mixture of regio isomers. Silica gel column chromatography of this mixture using 25% ethyl acetate in hexane afforded 2-benzyl-7-methyl-2,3-dihydro-isoindol-1-one (0.02 g, 9%); 1H NMR (300 MHz, CDCl3): δ ppm) 2.68 (s, 3H), 4.23 (s, 2H), 4.77 (s, 2H), 7.15-7.40 (m, 8H) and GC-MS: m/z 237 (M)+, 160 (M−77)+; and 2-benzyl-4-methyl-2,3-dihydro-isoindol-1-one (0.02 g, 9%); 1H NMR (300 MHz, CDCl3): δ (ppm) 2.68 (s, 3H), 4.23 (s, 2H), 4.77 (s, 2H), 7.15-7.40 (m, 8H) and GC-MS: m/z 237 (M)+, 160 (M−77)+.

1. temperaturewas heated
2. temperatureat reflux for 2.5 h
3. customthe solids removed by filtration
4. concentrationthe filtrate concentrated
5. dissolutionThe resulting material was dissolved in dichloromethane (20 mL)
6. washthe solution washed with brine (7 mL)
7. customThe organic solution was separated
8. dry with materialdried over anhydrous MgSO4
9. filtrationfiltered
10. concentrationconcentrated
11. customto afford
12. additiona mixture of regio isomers