反应详情

A 24.1 ml (38.6 mmole) of n-butyllithium.hexane solution was added dropwise to 10.0 g (38.6 mmole) of 1-bromo-2,5-dimethoxy-3,4,6-trimethylbenzene dissolved in anhydrous tetrahydrofuran (100 ml), under an atmosphere of argon at -40° C. over the period of 10 minutes, followed by stirring for another 20 minutes. Then, 3.32 g (38.6×0.6 mmole) of cuprous bromide was added, followed by stirring at -40° to -20° C. for 1 hour. After addition of a solution of 6.60 g (38.6 mmole)of benzyl bromide in tetrahydrofuran (15 ml), the cooling bath was removed, the reaction solution was stirred at 70° C. for 1 hour and cooled with ice, followed by addition of 1N hydrochloric acid (50 ml) and stirring. The tetrahydrofuran was distilled off under reduced pressure, and isopropyl ether was added to the residue. The insoluble matter was filtered through a bed of Hyflo Supercell, and the isopropyl ether layer was separated out, washed with water and aqueous sodium chloride solution successively, dried (magnesium sulfate) and evaporated. The residual solution was distilled under reduced pressure to give 8.62 g (83%) of 1-benzyl-2,5-dimethoxy-3,4,6-trimethylbenzene, b.p.140°-142° C. (0.3 torr) and m.p. 70° to 71° C.

1. stirringby stirring at -40° to -20° C. for 1 hour
2. customthe cooling bath was removed
3. stirringthe reaction solution was stirred at 70° C. for 1 hour
4. temperaturecooled with ice
5. additionfollowed by addition of 1N hydrochloric acid (50 ml)
6. stirringstirring
7. distillationThe tetrahydrofuran was distilled off under reduced pressure, and isopropyl ether
8. additionwas added to the residue
9. filtrationThe insoluble matter was filtered through a bed of Hyflo Supercell
10. customthe isopropyl ether layer was separated out
11. washwashed with water and aqueous sodium chloride solution successively
12. dry with materialdried (magnesium sulfate)
13. customevaporated
14. distillationThe residual solution was distilled under reduced pressure