反应详情

温度

0 °C

Ethyl acetoacetate (100 ml, 0.79 mole) in dry tetrahydrofuran (400 ml) was added dropwise with stirring under nitrogen to 50% sodium hydride (41.8 g, 0.87 mole) in dry tetrahydrofuran (80 ml) at 0° C. The resulting solution was stirred for 15 minutes at 0° C. before adding dropwise a solution of n-butyllithium in hexane (460 ml, 1.95 M; 0.90 mole). The resulting orange solution was stirred for a further 15 minutes at 0° C. before adding benzyl chloride (135 ml, 1.18 mole) in dry ether (200 ml) and the solution was then allowed to warm to room temperature over 11/4 hours with stirring before quenching reaction by addition of conc HCl acid (100 ml) in water (200 ml) followed by ether (500 ml). The layers were separated and the aqueous further extracted with ether (3×300 ml). The combined organic layers were washed with water until the wash was neutral, dried (anhydrous MgSO4) and then concentrated. The resulting yellow oil was distilled under vacuum to give a virtually colourless oil (64.2 g, 37%), b.p. 118°-126° C. at 0.7 mmHg, n.m.r. δ(CDCl3) 7.08 (5H, s), 4.07 (2H, q, J=7 Hz), 3.23 (2H, s), 2.80 (4H, s) and 1.23 (3H, t, J=7 Hz).

1. stirringThe resulting orange solution was stirred for a further 15 minutes at 0° C.
2. temperatureto warm to room temperature over 11/4 hours
3. stirringwith stirring
4. custombefore quenching
5. customreaction
6. customThe layers were separated
7. extractionthe aqueous further extracted with ether (3×300 ml)
8. washThe combined organic layers were washed with water until the wash
9. dry with materialdried (anhydrous MgSO4)
10. concentrationconcentrated
11. distillationThe resulting yellow oil was distilled under vacuum