反应详情

In a round bottomed flask, at −78° C., under argon atmosphere, a solution of DIPA (0.29 mL, 2.12 mmol) in dry THF (10 ml) was treated with n-BuLi (2.5 M in n-hexane, 0.776 mL, 1.94 mmol). After 30 min a solution of ethyl 2-(dibenzylamino)-acetate [prepared as described in Example 47, step 1] (0.5 g, 1.77 mmol) in dry THF (10 mL) was added dropwise via cannula. After 15 min, trimethylacetyl chloride (0.53 mL, 3.53 mmol) was added dropwise at −78° C. and the mixture stirred for 10 min at rt. The reaction was then quenched with H2O, and Et2O was subsequently added. The organic layer was washed with brine, dried over Na2SO4, filtered, and concentrated in vacuo to give a crude product as an oil. Purification by column chromatography using a Teledyne ISCO apparatus, eluting with Cy:AcOEt (98:2) gave the title compound (0.492 g, 76%) as a colorless oil. MS (ESI) m/z: 368 [M−H]+; (ESI) m/z: 366 [M−H]−. 1H NMR (DMSO-d6) δ 0.93 (s, 9H), 1.16-1.25 (m, 3H), 3.79 (d, J=13.97 Hz, 2H), 3.98 (d, J=13.96 Hz, 2H), 4.07-4.25 (m, 2H), 4.60 (s, 1H), 7.20-7.41 (m, 10H).

1. customThe reaction was then quenched with H2O, and Et2O
2. additionwas subsequently added
3. washThe organic layer was washed with brine
4. dry with materialdried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customto give a crude product as an oil
8. customPurification by column chromatography
9. washeluting with Cy