反应详情

A solution of ethyl N-(diphenylmethylene)glycinate (1.71 g, 6.40 mmol) in dry THF (10 ml) was added to a stirrred solution of LDA (2M in heptane/TNF/ethylbenzene, 320 ml, 6.40 mmol) in dry THF 910 ml) at −70° under nitrogen. After stirring at this temperture for 0.75 h, a solution of 5-benzenesulphonyloxy-2-bromomethylpyridine (2.00 g, 6.01 mmol); [prepared as described by Myers et al, J.O.C. 61, 813 (1996)] in dry THF (10 ml) was added. The reaction mixture was stirred at −70° for 1 h then at room temperature for 18 h. The reaction was quenched with water 910 ml) then partitioned between EtOAc (70 ml) and bring (30 ml). The phases were separated and the aqueous phase re-extracted with EtOAc (2×40 ml). The combined organic extracts were washed with brine (10 ml), dried (Na2SO4) and evaporated in vacuo to afford the crude product as a dark oil. Chromatography (silica: 60-75% Et2O/Hexane) afforded the title compound as a tan-coloured solid (2.25 g, 72%). δH (CDCl3) 8.02 (1H, d, J 2.8 Hz), 7.72 (2H, d, J 8.0 hz), 7.59 (1H, t, J 8.0 hz), 7.50 (2H, dd, J 8.4 Hz), 7.40-7.27 (8H, m), 7.19 (1H, dd, J 8.5, 2.8 Hz), 7.11 (1H, d, J 8.5 Hz), 6.67 (2H, br d, J 8.0 Hz), 4.50 (1H, dd, J 9.0, 4.6 Hz), 4.25-4.10 (2H, m), 3.50-3.33 (2H, m) and 1.24 (3H, t, J 7.2 Hz), m/z (ES+, 70V) 515 (MH+).

1. additionwas added
2. stirringThe reaction mixture was stirred at −70° for 1 h
3. waitat room temperature for 18 h
4. customThe reaction was quenched with water 910 ml)
5. customthen partitioned between EtOAc (70 ml)
6. customThe phases were separated
7. extractionthe aqueous phase re-extracted with EtOAc (2×40 ml)
8. washThe combined organic extracts were washed with brine (10 ml)
9. dry with materialdried (Na2SO4)
10. customevaporated in vacuo
11. customto afford the crude product as a dark oil