反应详情

A mixture of 58 parts of 5-methyl-1,3,4-thiadiazol-2-amine, 76 parts of 3-acetyl-4,5-dihydro-2(3H)-furanone, 1.2 parts of hydrochloric acid solution 12N and 540 parts of methylbenzene was stirred and refluxed for 2 hours using a water-separator. After cooling to room temperature, there were added dropwise 340 parts of phosphoryl chloride at 20°-40° C. (cooling was necessary to keep that temperature). The whole was gradually heated to reflux: at 95° C. Hydrogen chloride gas evolution was started. Then 100 parts of the mixture were distilled off and the residue was stirred and refluxed for 2 hours. After cooling, the reaction mixture was evaporated and the residue was poured into an ice/ammonium hydroxide mixture while stirring. The product was extracted with trichloromethane. The extract was dried, filtered and evaporated. The residue was purified three times by column-chromatography over silica gel using each time a mixture of trichloromethane and methanol (95:5 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was crystallized from 2,2'-oxybispropane, yielding 11.8 parts of 6-(2-chloroethyl)-2,7-dimethyl-5H-1,3,4-thiadiazolo[3,2-a]pyrimidin-5-one; mp. 118° C. (int. 14).

1. temperaturerefluxed for 2 hours
2. temperaturecooling
3. temperatureThe whole was gradually heated
4. temperatureto reflux
5. customat 95° C
6. distillationThen 100 parts of the mixture were distilled off
7. stirringthe residue was stirred
8. temperaturerefluxed for 2 hours
9. temperatureAfter cooling
10. customthe reaction mixture was evaporated
11. additionthe residue was poured into an ice/ammonium hydroxide mixture
12. stirringwhile stirring
13. extractionThe product was extracted with trichloromethane
14. customThe extract was dried
15. filtrationfiltered
16. customevaporated
17. customThe residue was purified three times by column-chromatography over silica gel using each time
18. additiona mixture of trichloromethane and methanol (95:5 by volume) as eluent
19. customThe pure fractions were collected
20. customthe eluent was evaporated
21. customThe residue was crystallized from 2,2'-oxybispropane