反应详情

70.7 g (300 mmol) of 1-ethoxy-2-(2,6-difluorophenyl)-1-imino-ethane hydrochloride are added, while stirring, to a suspension of 30.9 g (300 mmol) of oxalic acid monoamide monohydrazide in 900 ml of N,N-dimethylformamide. The reaction mixture is heated to 80° and stirred at this temperature for 1 hour. During a period of 20 minutes 10.6 g of methylamine are passed into the resulting white suspension, which leads to the formation of a clear yellow solution. During a period of 1 hour a further 15.9 g of methylamine are passed into the solution. The solution is then stirred for another hour at 80°. The solvent is evaporated in vacuo. 400 ml of water are added to the residue. The aqueous mixture is stirred and the crystals are filtered off. 300 ml of water are added to the crystals. The mixture is again stirred and the crystals are filtered off. The crystals are dissolved in hot ethanol (ca. 500 ml). After the addition of activated charcoal the mixture is filtered over Hyflo. The filtrate is evaporated until crystallisation starts (ca. 230 ml of ethanol have to be distilled off). The mixture is then cooled in an ice bath. The crystals are filtered off and dried overnight in vacuo, yielding the product of example 1.

1. temperatureThe reaction mixture is heated to 80°
2. stirringThe solution is then stirred for another hour at 80°
3. customThe solvent is evaporated in vacuo
4. addition400 ml of water are added to the residue
5. stirringThe aqueous mixture is stirred
6. filtrationthe crystals are filtered off
7. addition300 ml of water are added to the crystals
8. stirringThe mixture is again stirred
9. filtrationthe crystals are filtered off
10. dissolutionThe crystals are dissolved in hot ethanol (ca. 500 ml)
11. additionAfter the addition of activated charcoal the mixture
12. filtrationis filtered over Hyflo
13. customThe filtrate is evaporated until crystallisation
14. distillation(ca. 230 ml of ethanol have to be distilled off)
15. temperatureThe mixture is then cooled in an ice bath
16. filtrationThe crystals are filtered off
17. customdried overnight in vacuo