反应详情

A mixture of 19.5 g of the thus obtained 2-heptylthio-7-hydroxy-6-methyl-5H-1,3,4-thiadiazolo[3,2-a]pyrimidin-5-one, 38 g of phosphorus oxychloride and 13.6 g of phosphorus pentachloride was warmed to 77°~88° C. and was stirred for 2 hours. The reaction solution was concentrated under reduced pressure, thereafter the residue was dissolved in toluene, and the solution was washed with a potassium carbonate aqueous solution and water respectively. After the solution was dried over anhydrous sodium sulfate, the solvent was distilled off and the residue was purified by column chromatography on a silica gel column with an ethyl acetate/n-hexane (2:3) mixture as an eluent. After the solvent was distilled off, 19.0 g of 7-chloro-2-heptylthio-6-methyl-5H-1,3,4-thiadiazolo[3,2-a]pyrimidin-5-one was obtained. m.p. 79°~81° C. Yield 92%.

1. temperaturewas warmed to 77°~88° C.
2. concentrationThe reaction solution was concentrated under reduced pressure
3. dissolutionthe residue was dissolved in toluene
4. washthe solution was washed with a potassium carbonate aqueous solution and water respectively
5. dry with materialAfter the solution was dried over anhydrous sodium sulfate
6. distillationthe solvent was distilled off
7. customthe residue was purified by column chromatography on a silica gel column with an ethyl acetate/n-hexane (2:3) mixture as an eluent
8. distillationAfter the solvent was distilled off