反应详情

To a solution of 11 (2.35 g) in CH2Cl2 (25 ml) is added 25 ml of TFA and the mixture is stirred at room temperature for 24 h. The mixture is then concentrated and the residue is dissolved in ether (250 ml). Water (225 ml) is added followed by 1N NaOH (25 ml). After washing and separation, the basic water layer is extracted once more with ether. The water layer is acidified with conc. HCl and the precipitated product is extracted with ether (2×150 ml). The combined organic layers are washed with brine, dried and concentrated. 1.85 g of 12 is obtained as a cream colored solid.

1. concentrationThe mixture is then concentrated
2. dissolutionthe residue is dissolved in ether (250 ml)
3. additionWater (225 ml) is added
4. washAfter washing
5. customseparation
6. extractionthe basic water layer is extracted once more with ether
7. extractionthe precipitated product is extracted with ether (2×150 ml)
8. washThe combined organic layers are washed with brine
9. customdried
10. concentrationconcentrated