反应详情

To a stirred mixture of 2,4-dichloro-5-nitropyrimidine (4, 12 g, 62.1 mmol), potassium carbonate (11.7 g, 84.78 mmol) in acetone (100 mL) was added methyl N-1,4-dioxaspiro[4.5]dec-8-yl-D-alaninate (13.8 g, 62.1 mmol) at rt. The reaction mixture was stirred for 16 h at rt. The bulk of solvent was removed under reduced pressure to give a residue, which was diluted with ethyl acetate (100 mL), washed with water, dried over sodium sulfate. The solvent was evaporated to give a crude material, which was then purified by silica gel flash chromatography (eluent: ethyl acetate-hexane mixture (v:v=5:95)) to afforded the desired product (10.1 g). 1HNMR (300 MHz, CDCl3): δ 1.55-1.64 (m, 3H), 1.70-1.99 (m, 6H), 2.05-2.20 (m, 3H), 3.06-3.15 (m, 1H), 3.75 (s, 3H), 3.99 (t, 4H), 8.61 (s, 1H).

1. customThe bulk of solvent was removed under reduced pressure
2. customto give a residue, which
3. washwashed with water
4. dry with materialdried over sodium sulfate
5. customThe solvent was evaporated
6. customto give a crude material, which
7. customwas then purified by silica gel flash chromatography (eluent: ethyl acetate-hexane mixture (v:v=5:95))