反应详情

Triisopropylsilyl chloride (2.50 mL, 11.7 mmol) was added to a solution of diol 131 (3.11 g, 11.1 mmol) and imidazole (1.66 g, 24.4 mmol) in anhydrous DMF (30 mL) under N2 and then the mixture was stirred at room temperature for 18 h. The resulting mixture was added to ice-water (200 mL) and extracted with EtOAc (4×200 mL). The extracts were washed with water (200 mL) and then evaporated to dryness and the residue was chromatographed on silica gel. Elution with 0-20% EtOAc/petroleum ether firstly gave foreruns, and then further elution with 20-33% EtOAc/petroleum ether gave 4-(2-bromo-4-nitro-1H-imidazol-1-yl)-1-[(triisopropylsilyl)oxy]-2-butanol (132) (4.60 g, 95%) as a white solid: mp (CH2Cl2/pentane) 90-91° C.; 1H NMR (CDCl3) δ 7.89 (s, 1H), 4.24 (dd, J=7.7, 6.2 Hz, 2H), 3.74 (dd, J=9.6, 3.5 Hz, 1H), 3.62 (m, 1H), 3.53 (dd, J=9.6, 6.8 Hz, 1H), 2.59 (d, J=3.8 Hz, 1H), 1.95-1.82 (m, 2H), 1.17-1.03 (m, 21H). Anal. (C16H30BrN3O4Si) C, H, N.

1. extractionextracted with EtOAc (4×200 mL)
2. washThe extracts were washed with water (200 mL)
3. customevaporated to dryness
4. customthe residue was chromatographed on silica gel
5. washElution with 0-20% EtOAc/petroleum ether firstly gave foreruns
6. washfurther elution with 20-33% EtOAc/petroleum ether