反应详情

Into a flame-dry 500 ml 3-neck flask provided with mechanical stirrer, dropping funnel and a nitrogen inlet tube was placed 4.21 g sodium hydride (55% dispersion in oil, 100 mmol) with the apparatus placed under nitrogen. The oil was washed out with benzene (3×30 ml), 40 ml dry dimethylformamide was added and the suspension was stirred and cooled in an ice-bath. A solution of 21.6 g (100 mmol) 1-allyl-3,4-dihydro-7-methoxy-2(1H)naphthalenone (VIIIa) in 10 ml dimethylformamide was added dropwise (10 min), then the cooling bath was removed and stirring at room temperature continued until the evolution of gas ceased (2 hr). The brown-colored reaction mixture was cooled (ice-bath) and a solution of 16.7 g (100 mmol) ethyl bromoacetate in 40 ml dimethylformamide was added dropwise keeping the reaction temperature below 25° C. After the addition (15-20 min) stirring in cold was continued for 1 hr and then overnight at room temperature. Water (300 ml) was added and extracted with ether (3×100 ml). The combined ether extracts were washed with water (2×100 ml) dried (MgSO4), the solvent removed by evaporation and the residue was distilled to give 26.0 g (86%) IXa, b.p. 145°-150°/0.05-0.01 mm Hg; IR (neat) 1740, 1715 cm-1 ; NMR δ, 1.05 and 3.92 (triplet and quartet for OCH2CH3), 3.75 (s, 3, OCH3), 4.65-6.0 (m, 3, CH=CH2), 6.55-7.15 (m, 3, ArH).

1. customInto a flame-dry 500 ml 3-neck flask provided with mechanical stirrer
2. washThe oil was washed out with benzene (3×30 ml), 40 ml dry dimethylformamide
3. additionwas added
4. temperaturecooled in an ice-bath
5. customthe cooling bath was removed
6. stirringstirring at room temperature
7. custom(2 hr)
8. temperatureThe brown-colored reaction mixture was cooled (ice-bath)
9. customthe reaction temperature below 25° C
10. additionAfter the addition (15-20 min)
11. stirringstirring in cold
12. customovernight
13. customat room temperature
14. extractionextracted with ether (3×100 ml)
15. washThe combined ether extracts were washed with water (2×100 ml)
16. dry with materialdried (MgSO4)
17. customthe solvent removed by evaporation
18. distillationthe residue was distilled
19. customto give 26.0 g (86%) IXa, b.p. 145°-150°/0.05-0.01 mm Hg