反应详情

A solution of (±)-tert-butyl 4-(4-chlorophenyl)-4-hydroxy-3,3-dimethylpiperidine-1-carboxylate (93.7 g, 0.276 mol) in dioxane (100 mL) was treated with 4 M HCl solution in dioxane (275 mL, 1.1 mol). The resulting mixture was stirred at room temperature for four hours. After this time, the mixture was concentrated in vacuo, and then concentrated 3× from methylene chloride (200 mL) to remove residual HCl. The resulting residue was stirred in 1 M NaOH (500 mL), and the resulting suspension was extracted 4× with 500 mL of ethyl acetate. The combined organic phases were washed with brine, dried over sodium sulfate, and concentrated in vacuo to yield the title compound (66.8 g, quantitative yield) as a solid.

1. concentrationAfter this time, the mixture was concentrated in vacuo
2. concentrationconcentrated 3× from methylene chloride (200 mL)
3. customto remove residual HCl
4. stirringThe resulting residue was stirred in 1 M NaOH (500 mL)
5. extractionthe resulting suspension was extracted 4× with 500 mL of ethyl acetate
6. washThe combined organic phases were washed with brine
7. dry with materialdried over sodium sulfate
8. concentrationconcentrated in vacuo