反应详情

Seven (7.0) grams of the thus obtained 2-amino-5-hexylthio-1,3,4-thiadiazole and 4.3 g of ethyl acetoacetate were mixed with 8 g of polyphosphoric acid, and the mixture was heated to 130°-150° C. and stirred for 30 minutes. After cooling, water was added to the reaction mixture, and the resulting mixture was extracted with chloroform. The organic layer was washed with a sodium hydrogen carbonate aqueous solution and water respectively, dried over anhydrous sodium sulfate. The solvent was distilled off. The residue was purified by developing on a silica gel column, and eluting with an ethylacetate/n-hexane (1:1) mixture, and thus 7.5 g of 2-hexylthio-7-methyl-5H-1,3,4-thiadiazolo[3,2-a]pyrimidin-5-one was obtained. Refraction index nD20 : 1.6003. Yield 82%.

1. temperaturethe mixture was heated to 130°-150° C.
2. temperatureAfter cooling
3. extractionthe resulting mixture was extracted with chloroform
4. washThe organic layer was washed with a sodium hydrogen carbonate aqueous solution and water respectively
5. dry with materialdried over anhydrous sodium sulfate
6. distillationThe solvent was distilled off
7. customThe residue was purified
8. washeluting with an ethylacetate/n-hexane (1:1) mixture