反应详情

53.5 g of benzylamine and 59 g of hydrazodicarbonamide are stirred in 100 ml of N-methyl pyrrolidone for 4 hours at 175° C. and for 5 hours at 200° C. The solvent is then distilled off in vacuo, the residue is triturated with 50 ml of a 10% sodium hydroxide solution and the residue is isolated by filtration under suction. The filtrate is neutralised with 10% hydrochloric acid. A deposit is formed which is filtered off under suction and washed with water, giving 67 g (70% of the theoretical yield) of 4-benzyl-1,2,4-triazolidine-3,5-dione in the form of colourless crystals melting at 185° to 188° C. (CH3CN).

1. distillationThe solvent is then distilled off in vacuo
2. customthe residue is triturated with 50 ml of a 10% sodium hydroxide solution
3. customthe residue is isolated by filtration under suction
4. customA deposit is formed which
5. filtrationis filtered off under suction
6. washwashed with water
7. customgiving 67 g (70% of the