反应详情

53.5 g of benzylamine and 59 g of hydrazodicarboxamide in 100 ml of N-methylpyrrolidone are stirred at 175° C. for 4 hours and at 200° C. for 5 hours. The solvent is then distilled off in vacuo, the residue is triturated with 50 ml of 10% strength sodium hydroxide solution, and the resulting residue is filtered off. The filtrate is neutralised with 10% strength hydrochloric acid. A precipitate is thereby formed and is filtered off and washed with water. 67 g (70% of the theoretical yield) of 4-benzyl-1,2,4-triazolidine-3,5-dione are obtained as colourless cyrstals of melting point 185°-188° C. (CH3CN).

1. distillationThe solvent is then distilled off in vacuo
2. customthe residue is triturated with 50 ml of 10% strength sodium hydroxide solution
3. filtrationthe resulting residue is filtered off
4. customA precipitate is thereby formed
5. filtrationis filtered off
6. washwashed with water