反应详情

A 1.75N NaOH solution (39.52 mmol, 22.58 ml) was added to a suspension of 2-thioxo-2,3-dihydropyrazolo[1,5-a][1,3,5]triazin-4(1H)-one (3.32 g, 19.76 mmol) from 1b in absolute EtOH (80 mL). Methyl iodide (2.80 g, 19.76 mmol) was then added and the reaction mixture was allowed to stir for 2 hours at room temperature. The resulting precipitate was collected by vacuum filtration, suspended in water (110 mL) and acidified with 2NH2SO4. The solution was stirred at 0° C. for 5 minutes and the new precipitate was collected by vacuum filtration, washed with cold water, and then air dried to give 1.88 g (52%) of 2-(methylthio)pyrazolo[1,5-a][1,3,5]triazin-4(3H)-one.

1. filtrationThe resulting precipitate was collected by vacuum filtration
2. stirringThe solution was stirred at 0° C. for 5 minutes
3. filtrationthe new precipitate was collected by vacuum filtration
4. washwashed with cold water
5. customair dried