反应详情

320 mg (1.5 mmol) of 1-ethoxy-2-(2,6-difluorophenyl)-1-(N-methylimino)-ethane and 155 mg (1.5 mmol) of oxalic acid monoamide monohydrazide are dissolved under a nitrogen atmosphere in 5 ml of N-methylmorpholine and the whole is heated under reflux for 41 hours. After cooling, the reaction mixture is diluted with 20 ml of dichloromethane and extracted by shaking in succession twice with water, twice with 2N hydrochloric acid and again with water The last three acidic aqueous phases obtained are combined, rendered alkaline with concentrated ammonia solution and extracted three times with dichloromethane. The combined organic phases are dried over magnesium sulphate and concentrated. Recrystallisation of the crude product from ethanol yields 102 mg (27% of the theoretical yield) of the desired 5-(2,6-difluorobenzyl)-4-methyl-4H-1,2,4-triazole-3-carboxamide which melts at 189°-190°.

1. temperaturethe whole is heated
2. temperatureunder reflux for 41 hours
3. temperatureAfter cooling
4. extractionextracted
5. customobtained
6. extractionextracted three times with dichloromethane
7. dry with materialThe combined organic phases are dried over magnesium sulphate
8. concentrationconcentrated
9. customRecrystallisation of the crude product from ethanol
10. customyields 102 mg (27% of the