反应详情

5.16 g of 1-benzyl-4-carbamoyloxy-4-ethynylpiperidine are stirred in 30 ml of 30% by weight solution of hydrogen bromide in acetic acid at room temperature for 6 hours. After evaporating the solvent under reduced pressure and adding 50 ml of water to the residue the base is liberated by sodium hydrogen carbonate. The solid product obtained is filtered, washed to bromide-free with water, dried and recrystallized from n-hexane to give the title compound in 59.3% yield the physical characteristics of which are in agreement with those given in Example 1.

1. customAfter evaporating the solvent under reduced pressure
2. additionadding 50 ml of water to the residue the base
3. customThe solid product obtained
4. filtrationis filtered
5. washwashed to bromide-free with water
6. customdried
7. customrecrystallized from n-hexane