反应详情

A stirred solution of methyl N-(2-chloro-5-nitropyrimidin-4-yl)-N-1,4-dioxaspiro[4.5]dec-8-yl-D-alaninate (17 g, 42.5 mmol) in dioxane (450 mL, contains 1M HCl) was heated to reflux for 16 h. The bulk of solvent was then removed under reduced pressure, the crude material was neutralized with aq. NaHCO3, and extracted with ethyl acetate (300 mL×3). Organic layers were combined, dried over sodium sulfate, and evaporated to give the crude material, which was then purified by silica gel column chromatography to give the desired product (10 g). 1HNMR (300 MHz, CDCl3): δ 1.66 (d, J=6.9 Hz, 3H), 1.99-2.18 (m, 2H), 2.34-2.57 (m, 6H), 3.56-3.59 (m, 1H), 3.76 (s, 3H), 4.04 (q, J=6.9, 13.8 Hz, 1H), 8.70 (s, 1H).

1. temperatureto reflux for 16 h
2. customThe bulk of solvent was then removed under reduced pressure
3. extractionextracted with ethyl acetate (300 mL×3)
4. dry with materialdried over sodium sulfate
5. customevaporated
6. customto give the crude material, which
7. customwas then purified by silica gel column chromatography