反应详情

Diethylazodicarboxylate (0.070 mL, 0.45 mmol) was added dropwise to a suspension of oxazine alcohol 134 (see Example 2BB above) (251 mg, 1.26 mmol), triphenylphosphine (448 mg, 1.71 mmol), and 4-iodophenol (377 mg, 1.71 mmol) in anhydrous THF (3.0 mL) at 0° C. under N2, and the resulting mixture was stirred at room temperature for 32 h. The solvent was removed and the residue was chromatographed on silica gel. Elution with CH2Cl2 firstly gave foreruns, and then further elution with 0-2% EtOAc/CH2Cl2 gave a crude solid, which was further chromatographed on silica gel. Elution with 0-50% EtOAc/petroleum ether firstly gave foreruns, and then further elution with 10% MeOH/CH2Cl2 gave 7-[(4-iodophenoxy)methyl]-2-nitro-6,7-dihydro-5H-imidazo[2,1-b][1,3]oxazine (135) (433 mg, 86%) as a cream solid: mp (MeOH/CH2Cl2/hexane) 224-227° C.; 1H NMR [(CD3)2SO] δ 8.08 (s, 1H), 7.62 (dt, J=9.0, 2.7 Hz, 2H), 6.86 (dt, J=9.0, 2.7 Hz, 2H), 4.89 (m, 1H), 4.31 (dd, J=11.1, 3.4 Hz, 1H), 4.25 (dd, J=11.1, 5.8 Hz, 1H), 4.18 (ddd, J=12.6, 5.8, 3.0 Hz, 1H), 4.09 (ddd, J=12.5, 10.8, 5.2 Hz, 1H), 2.35-2.26 (m, 1H), 2.25-2.12 (m, 1H). Anal. (C13H12IN3O4) C, H, N.

1. customThe solvent was removed
2. customthe residue was chromatographed on silica gel
3. washElution with CH2Cl2 firstly gave foreruns
4. washfurther elution with 0-2% EtOAc/CH2Cl2
5. customgave a crude solid, which
6. customwas further chromatographed on silica gel
7. washElution with 0-50% EtOAc/petroleum ether firstly gave foreruns
8. washfurther elution with 10% MeOH/CH2Cl2