反应详情

A mixture of 20.75 g of the compound obtained in step A) and 10 g of iron powder in 19 ml of water and 19 ml of ethanol is brought to the reflux point. A solution of 37.5 ml of concentrated hydrochloric acid in 25 ml of water and 25 ml of ethanol is added dropwise to this mixture and reflux is maintained for 1 hour 30 minutes. After cooling, the reaction mixture is poured onto ice and then treated with a saturated solution of NaHCO3 and extracted with AcOEt. The extract is washed with water and dried over Na2SO4 and the solvent is evaporated off under vacuum. The residue is chromatographed on silica using a DCM/MeOH mixture (92/8; v/v) as the eluent. 12.71 g of the expected product are obtained after crystallization from isopropyl ether. M.p.=108° C.

1. temperaturereflux
2. temperatureis maintained for 1 hour 30 minutes
3. temperatureAfter cooling
4. additionthe reaction mixture is poured onto ice
5. extractionextracted with AcOEt
6. washThe extract is washed with water
7. dry with materialdried over Na2SO4
8. customthe solvent is evaporated off under vacuum
9. customThe residue is chromatographed on silica using a DCM/MeOH mixture (92/8; v/v) as the eluent