反应详情

143 g (0.5 mole) of β-(2-methyl-6-phenyl-imidazo[2,1-b]-1,3,4-thiadiazol-5-yl)-propenoic acid were suspended in 1.5 liters of absolute toluene at 60° to 70° C. 50 ml of thionyl chloride were added dropwise, a clear solution resulting. The solution was then heated under reflux for 2 hours and subsequently cooled to room temperature. 220 ml (1.5 moles) of 2-ethylpiperidine were next added dropwise and the mixture was boiled under reflux for one hour. The cooled mixture was filtered (the residue was discarded) and the filtrate was extracted twice with 300 ml of water. The toluene phase was dried over sodium sulphate and filtered and the filtrate was concentrated by distillation. The residue was recrystallised from 400 ml of ethyl acetate.

1. customa clear solution resulting
2. temperatureThe solution was then heated
3. temperatureunder reflux for 2 hours
4. temperatureunder reflux for one hour
5. filtrationThe cooled mixture was filtered (the residue
6. extractionwas extracted twice with 300 ml of water
7. dry with materialThe toluene phase was dried over sodium sulphate
8. filtrationfiltered
9. concentrationthe filtrate was concentrated by distillation
10. customThe residue was recrystallised from 400 ml of ethyl acetate