反应详情

1.0 of 6,7-diamino-2-(4-tert-butylphenyl)-5H-[1,3,4]thiadiazolo[3,2-a]pyrimidin-5-one was suspended in a mixture of 20 ml of concentrated hydrochloric acid and 20 ml of water, and 2 ml of an aqueous solution containing 0.70 g of sodium nitrite was added dropwise thereto while cooling below 5° C. and stirring. The mixture was stirred at that temperature for 1.5 hours and then diluted with water. The resulting precipitate was filtered and recrystallized from chloroform-ethanol to obtain 0.88 g of the titled compound as pale yellow prisms. Melting Point: 293°-296° C. (decomposition).

1. additionwas added dropwise
2. temperaturewhile cooling below 5° C.
3. stirringThe mixture was stirred at that temperature for 1.5 hours
4. filtrationThe resulting precipitate was filtered
5. customrecrystallized from chloroform-ethanol