反应详情

A solution of benzyl 4-(5-chloro-2-methoxyphenyl)piperidine-1-carboxylate (Preparation 234, 73 g, 0.2 mol) in concentrated hydrochloric acid (200 ml) was refluxed with stirring for 2 hours before concentrating in vacuo. Water (100 ml), sodium hydroxide (10 M aqueous solution, 20 ml) and chloroform (200 ml) were added to the residue. The aqueous layer was extracted with chloroform (2×200 ml). The combined organic layers were washed with water (200 ml), saturated aqueous sodium chloride solution (200 ml), dried over sodium sulphate, filtered through silica gel (100 g, 40/63 μm) and evaporated in vacuo to afford the title compound as white crystals, 40 g, 89% yield.

1. concentrationbefore concentrating in vacuo
2. additionWater (100 ml), sodium hydroxide (10 M aqueous solution, 20 ml) and chloroform (200 ml) were added to the residue
3. extractionThe aqueous layer was extracted with chloroform (2×200 ml)
4. washThe combined organic layers were washed with water (200 ml), saturated aqueous sodium chloride solution (200 ml)
5. dry with materialdried over sodium sulphate
6. filtrationfiltered through silica gel (100 g, 40/63 μm)
7. customevaporated in vacuo