反应详情

1.89 g of methylglyoxal (40% in water) are added to 2.71 g of N′-[(2,6-difluorophenyl)-iminomethyl]-hydrazinecarboxylic acid tert-butyl ester in 30 ml of ethanol and stirring is carried out at room temperature for 16 h. The reaction mixture is then concentrated, and the residue is taken up in 20 ml of formic acid and stirring is continued at room temperature for 5 h. The reaction mixture is concentrated by evaporation; the residue is again dissolved in 20 ml of ethanol, boiled under reflux for 2 h, then concentrated and purified by means of column chromatography. In this way 3-(2,6-difluorophenyl)-6-methyl-[1,2,4]triazine having a melting point of 90-93° C. is obtained.

1. concentrationThe reaction mixture is then concentrated
2. stirringstirring
3. waitis continued at room temperature for 5 h
4. concentrationThe reaction mixture is concentrated by evaporation
5. dissolutionthe residue is again dissolved in 20 ml of ethanol
6. temperatureunder reflux for 2 h
7. concentrationconcentrated
8. custompurified by means of column chromatography