[CH2:1]([N:4]([C:6]([NH:8][C:9]1[S:10][C:11]([O:14][CH3:15])=[N:12][N:13]=1)=[O:7])[NH2:5])[CH2:2][CH3:3].[CH2:16]=O.[OH-].[K+]>CO>[CH2:1]([N:4]1[C:6](=[O:7])[N:8]([C:9]2[S:10][C:11]([O:14][CH3:15])=[N:12][N:13]=2)[CH2:16][NH:5]1)[CH2:2][CH3:3]2-Propyl-4-(5-methoxy-1,3,4-thiadiazol-2-yl)-semicarbazide (0.1 mole) dissolved in methanol (100 ml) is charged into a glass reaction vessel equipped with a mechanical stirrer and thermometer. Aqueous formaldehyde (0.2 mole; 37% concentration) is then added to the reaction vessel with stirring. Dilute aqueous potassium hydroxide is added to the reaction mixture to adjust the pH to between 7 and 8 and stirring is continued for a period of about 20 minutes resulting in the formation of a solid precipitate. The precipitate is recovered by filtration, is recrystallized and is dried under vacuum to yield the desired product 2-propyl-4-(5-methoxy-1,3,4-thiadiazol-2-yl)-1,2,4-triazolidin-3-one.
Wird geladen…