反应详情

温度

-70 °C

n-Butyllithium (1.6M in hexane, 20.76 mL, 33.22 mmol) was added dropwise to 1-methyl-1H-imidazole (CAS no. 616-47-7) (3 g, 36.54 mmol), in THF (10 mL) cooled to −70° C. over a period of 10 minutes under nitrogen. The resulting solution was stirred at −70° C. for 10 minutes. di-tert-Butyl diazene-1,2-dicarboxylate (CAS no. 870-50-8) (7.65 g, 33.22 mmol) in THF (6 ml) added dropwise over 10 minutes, not allowing the solution to rise above −65° C. After the addition was complete the solution was allowed to warm to ambient temperature overnight. Water (20 mL) added at RT. The THF was removed under vacuum. Extracted with EtOAc (2×40 mL). The organic extracts were combined, washed with brine (15 mL), dried over MgSO4 and reduced to give crude product. The crude product was purified by flash silica chromatography eluting with 20 to 100% EtOAc in isohexane to afford the product (6.17 g, 59.5%). m/z (ESI+) (M+H)+=313; HPLC tR=1.36 min.

1. customto rise above −65° C
2. additionAfter the addition
3. temperatureto warm to ambient temperature overnight
4. customThe THF was removed under vacuum
5. extractionExtracted with EtOAc (2×40 mL)
6. washwashed with brine (15 mL)
7. dry with materialdried over MgSO4
8. customto give crude product
9. customThe crude product was purified by flash silica chromatography
10. washeluting with 20 to 100% EtOAc in isohexane