反应详情

温度

35 °C

The 2-methyl-4-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)semicarbazide prepared in Example 2 was dissolved in methanol (100 ml) in a glass reaction flask equipped with a mechanical stirrer and thermometer. Aqueous formaldehyde (12 ml; 37% concentration) was then added to the flask with stirring. The reaction mixture warmed to a temperature of about 35° C. Sufficient aqueous potassium hydroxide was then added to adjust the pH of the reaction medium to from about 7 to 8. A solid precipitate was formed. The precipitate was then recovered by filtration, was recrystallized from an ethyl acetate-heptane mixture and was dried under vacuum to yield the desired product 2-methyl-4-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)-1,2,4-triazolidin-3-one having a melting point of 187° to 188° C.

1. customequipped with a mechanical stirrer
2. customA solid precipitate was formed
3. filtrationThe precipitate was then recovered by filtration
4. customwas recrystallized from an ethyl acetate-heptane mixture
5. customwas dried under vacuum