反应详情

Crude 2-{2-chloro-1-[(triisopropylsilyl)oxy]ethenyl}pyridine (117.3 g, 0.376 mol) is placed in a 4 L plastic bottle and is dissolved in acetonitrile (0.4 L). To the stirring solution is added 48% aqueous HF (170 mL, 0.45 mL/mmol) and the progress of the reaction is monitored by reverse phase analytical HPLC. After. Ca. 2 hours the reaction is judged to be complete, and the pH of the solution is carefully adjusted to ca. 8 with saturated aq. NaHCO3. The mixture is poured into a separatory funnel containing CH2Cl2 (1.5 L). The organic phase is removed and the aq. layer is extracted with CH2Cl2 (2×1.0 L). The combined organic layers are dried (Na2SO4), and concentration in vacuo affords the title compound (49.5 g) as a tan solid (after cooling). The crude material is judged to be quite pure by 1H—NMR and HPLC and is used as is in the Noyori asymmetric reduction.

1. additionTo the stirring solution is added 48% aqueous HF (170 mL, 0.45 mL/mmol)
2. custom2 hours
3. additionThe mixture is poured into a separatory funnel
4. customThe organic phase is removed
5. extractionthe aq. layer is extracted with CH2Cl2 (2×1.0 L)
6. customThe combined organic layers are dried
7. concentration(Na2SO4), and concentration in vacuo