反应详情

温度

5 °C

A mixture of 37.7 g of 4-carboxy-4-phenylpiperidine p-toluenesulfonate, 53.3 g of 30% aqueous NaOH solution and 250 ml of water is cooled to 5° C. A solution of 18 g of benzyl chloroformate in 60 ml of acetone is added rapidly at 5° C. and the reaction mixture is stirred overnight, the temperature being allowed to rise to RT. It is washed twice with ether and, after decantation, the aqueous phase is acidified to pH 1 by the addition of concentrated HCl and then 2 N HCl. The precipitate formed is filtered off, dried, taken up with ether and filtered off again to give 30.6 g of the expected product, m.p.=142-144° C.

1. customto rise to RT
2. washIt is washed twice with ether
3. additionafter decantation, the aqueous phase is acidified to pH 1 by the addition of concentrated HCl
4. customThe precipitate formed
5. filtrationis filtered off
6. customdried
7. filtrationfiltered off again