反应详情

9.1 g of piperazin-1-yl-acetic acid morpholide are dissolved in 30 ml of water and 4.4 ml of concentrated hydrochloric acid and the solution is cooled to 20° C. A solution of 3.1 g of potassium cyanate in 15 ml of water is slowly added dropwise, with cooling. A further 4.4 ml of concentrated hydrochloric acid are then added and the mixture is left to stand overnight at 20° C. The solution is rendered neutral with 2N sodium hydroxide solution and concentrated. Boiling up of the solid residue with isopropanol and cooling of the solution gives 5.3 g of colourless crystals, which are recrystallised from ethanol.

1. temperaturewith cooling
2. waitthe mixture is left
3. concentrationconcentrated
4. temperaturecooling of the solution