反应详情

100 ml of concentrated hydrochloric acid are added to a suspension of 16 g of the compound obtained in Step 1 in 55 ml of ethanol. The mixture is cooled with ice and stirred whilst a solution of 62.6 g of SnCl2.2H2O in 100 ml of ethanol is being introduced and then for a further 3 hours. After removal of the solvent by evaporation, the residue is diluted with 140 ml of ice-cold water and rendered basic with 2N sodium hydroxide solution. The resulting aqueous phase is extracted 3 times with 350 ml of methylene chloride each time. The combined organic phases are dried over MgSO4 and evaporated. The residue is purified by flash chromatography (CH2Cl2/MeOH: 98/2) to yield the expected product.

1. temperatureThe mixture is cooled with ice
2. additionis being introduced
3. customAfter removal of the solvent
4. customby evaporation
5. additionthe residue is diluted with 140 ml of ice-cold water
6. extractionThe resulting aqueous phase is extracted 3 times with 350 ml of methylene chloride each time
7. dry with materialThe combined organic phases are dried over MgSO4
8. customevaporated
9. customThe residue is purified by flash chromatography (CH2Cl2/MeOH: 98/2)