反应详情

温度

85 °C

A solution of lithium (77 mg) in methanol (30 ml) was added during 2 hours to a stirred suspension of 2-cyanobenzaldehyde and (1,3-dioxolan-2-yl-methyl)-triphenyl phosphonium bromide (4.71 g) in dimethylformamide (34 ml) at 85° C. The mixture was stirred at 85° C. for 6 hours, allowed to cool and poured into water (450 ml). The reaction mixture was extracted with diethyl ether (3×120 ml) and the combined ether extracts washed with saturated brine, dried (MgSO4) and evaporated. The residue was dissolved and stirred in tetrahydrofuran (30 ml) and 3M hydrochloric acid (30 ml) for 2 hours. The mixture was diluted with water (100 ml) and extracted with diethyl ether (300 ml). The ether was washed with saturated sodium hydrogen carbonate solution (2×50 ml) and saturated brine, dried (MgSO4) and evaporated. The residue was purified by flash column chromatography on silica, eluting with n-hexane/ethyl acetate (80:20:, by volume) to give as a pale yellow solid 2-cyano-(E)-cinnamaldehyde (504 mg, 45%) m.p. 107°-110° C.; NMR: 6.82 (1H, q), 7.69 (5H, m) and 9.81 (1H, d); m/e 157 (M+).

1. temperatureto cool
2. extractionThe reaction mixture was extracted with diethyl ether (3×120 ml)
3. washthe combined ether extracts washed with saturated brine
4. dry with materialdried (MgSO4)
5. customevaporated
6. dissolutionThe residue was dissolved
7. stirringstirred in tetrahydrofuran (30 ml)
8. wait3M hydrochloric acid (30 ml) for 2 hours
9. additionThe mixture was diluted with water (100 ml)
10. extractionextracted with diethyl ether (300 ml)
11. washThe ether was washed with saturated sodium hydrogen carbonate solution (2×50 ml) and saturated brine
12. dry with materialdried (MgSO4)
13. customevaporated
14. customThe residue was purified by flash column chromatography on silica
15. washeluting with n-hexane/ethyl acetate (80:20:, by volume)