反应详情

温度

-5 °C

To a solution of acetic acid (7.5 mL) and hydrochloric acid, 37% (1.5 mL) was added Intermediate 71A (1.49 g, 9.13 mmol). The suspension was cooled to −5° C. A solution of sodium nitrite (0.882 g, 12.79 mmol) in water (2 mL) was added dropwise. The resulting mixture was stirred at 0° C. for 2 hours. A mixture of copper (II) chloride (0.31 g, 2.28 mmol) in acetic acid (15 mL) was saturated with sulfur dioxide by bubbling for 40 min. The reaction mixture containing the diazonium salt was slowly poured into the copper (II) chloride-SO2 mixture. The resulting mixture was stirred at 0° C. for 30 minutes, diluted with ice-water, and extracted with DCM (three times). The combined organic layers were dried over MgSO4, filtered and concentrated to give Intermediate 71B (1.9 g, 84%) as yellow oil. HPLC: Rt=1.622 min. (CHROMOLITH® column 4.6×50 mm eluting with 10-90% aqueous methanol over 4 min. containing 0.1% TFA, 4 mL/min., monitoring at 220 nm).

1. customby bubbling for 40 min
2. additionThe reaction mixture containing the diazonium salt
3. additionwas slowly poured into the copper (II) chloride-SO2 mixture
4. stirringThe resulting mixture was stirred at 0° C. for 30 minutes
5. additiondiluted with ice-water
6. extractionextracted with DCM (three times)
7. dry with materialThe combined organic layers were dried over MgSO4
8. filtrationfiltered
9. concentrationconcentrated