反应详情

A solution of 8.6 g of the thus obtained 7-chloro-2-heptylthio-6-methyl-5H-1,3,4-thiadiazolo[3,2-a]pyrimidin-5-one, 3.0 g of spray dry potassium fluoride and 32 ml of sulfolane was heated at 205°~225° C. in a stream of nitrogen for 1 and half hours. After cooling, water was added to the mixture, and the mixture was extracted with toluene. The toluene layer was collected and washed with water. The toluene phase was dried over anhydrous sodium sulfate, the solvent was distilled off. The residue was purified by column chromatography on a silica gel column with an ethyl acetate/n-hexane (1:3) mixture as an eluent. After the solvent was distilled off, 5.2 g of 7-fluoro-2-heptylthio-6-methyl-5H-1,3,4-thiadiazolo[3,2-a]pyrimidin-5-one was obtained. m.p. 78°~91° C. Yield 63%.

1. temperatureAfter cooling
2. extractionthe mixture was extracted with toluene
3. customThe toluene layer was collected
4. washwashed with water
5. dry with materialThe toluene phase 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 (1:3) mixture as an eluent
8. distillationAfter the solvent was distilled off