反应详情

Part A. A solution of 4-nitro-o-xylene (38.64 g, 255.9 mmol), NBS (91.1 g, 511.8 mmol), benzoyl peroxide (1.239 g, 5.118 mmol), and CCl4 (400 mL) was heated at reflux for 1 day, then at rt for 2 days. The solid was filtered off and washed with CCl4. The filtrate was evaporated to give the crude dibromo product (80 g). A portion of which (20 g) was dissolved in acetone (170 mL) and water (45 mL), then Na2CO3 (43.1 g, 407 mmol) was slowly added, followed by BnNH2 (7.05 mL, 64.6 mmol) in acetone (22 mL). After 10 h, the solution was concentrated to one-fourth its volume, the salt solid was filtered off, and the filtrate was evaporated. The residue was dissolved in EtOAc, washed with water and brine, dried over sodium sulfate, filtered, and evaporated. The residue was purified by column chromatography to provide the corresponding 2-benzyl-5-nitro-2,3-dihydro-1H-isoindole (5.41 g, 33% yield, over 2 steps): 1H NMR (300 MHz, CDCl3) δ 8.11 (d, 1H), 8.04 (s, 1H), 7.48–7.20 (m, 6H), 4.02 (s, 4H), 3.92 (s, 2H).

1. temperatureat reflux for 1 day
2. filtrationThe solid was filtered off
3. washwashed with CCl4
4. customThe filtrate was evaporated
5. customto give the crude dibromo product (80 g)
6. waitAfter 10 h
7. concentrationthe solution was concentrated to one-fourth its volume
8. filtrationthe salt solid was filtered off
9. customthe filtrate was evaporated
10. dissolutionThe residue was dissolved in EtOAc
11. washwashed with water and brine
12. dry with materialdried over sodium sulfate
13. filtrationfiltered
14. customevaporated
15. customThe residue was purified by column chromatography