反应详情

A mixture of 1.5 g of 1-amidino-4-piperidinecarboxylic acid hydrochloride and 8.8 g of bis-(p-chlorophenyl)sulfite was stirred at room temperature for 1 hour in a solution of 14 ml of dry dimethylformamide and 7 ml of dry pyridine. The solvent was removed under reduced pressure, and the residue was washed twice with dry ether. Acetone was added to the residue to give crystals. The crystals were washed with ether and then with ethyl acetate and recrystallized from methanol-ether to obtain 1.62 g (yield: 70.4%) of p-chlorophenyl 1-amidino-4-piperidinecarboxylate hydrochloride as colorless crystals having a melting point of 196° to 198° C.

1. customThe solvent was removed under reduced pressure
2. washthe residue was washed twice with dry ether
3. additionAcetone was added to the residue
4. customto give crystals
5. washThe crystals were washed with ether
6. customwith ethyl acetate and recrystallized from methanol-ether