反应详情

To a solution of the product from Example 17, step c) (199 mg, 0.79 mmol) in CHCl3 (3 ml) and AcOH (3 ml) was added NBS (156 mg, 0.88 mmol). The reaction mixture was stirred for 30 minutes, quenched with saturated NaHCO3 (10 ml), and extracted with EtOAc (20 ml). The EtOAc layer was dried (MgSO4), filtered, and solvent evaporated in vacuo to give the crude product that was purified by silica-gel preparative TLC (hexanes:EtOAc-3:1) providing the subtitle compound (99.6 mg, 36%). 1H NMR (300 MHz, CDCl3, ppm) 1.22 (t, J=7 Hz, 3H); 2.42 (br s, 1H); 2.63-2.78 (m, 1H); 2.95-3.18 (m, 2H); 3.30-3.48 (br m, 1H); 3.50-3.72 (br m, 2H); 3.75-3.88 (br m, 2H); 4.08 (q, J=7 Hz, 2H); 4.52 (s, 2H).

1. customquenched with saturated NaHCO3 (10 ml)
2. extractionextracted with EtOAc (20 ml)
3. dry with materialThe EtOAc layer was dried (MgSO4)
4. filtrationfiltered
5. customsolvent evaporated in vacuo
6. customto give the crude product that
7. customwas purified by silica-gel preparative TLC (hexanes:EtOAc-3:1)