反应详情

3.01 g. of 8-ethyl-2-methylthio-4H-pyrazolo[4',3':5,6]pyrido[3,4-e][1,2,4]triazolo[1,5-a]pyrimidin-5(8H)-one obtained in Example 10a are oxidized with 2.2 g. of sodium metaperiodate in aqueous alcohol for 7 days at room temperature. The precipitate of 8-ethyl-2-methylsulfinyl-4H-pyrazolo[4',3':5,6]pyrido[3,4-e][1,2,4]triazolo[1,5-a]pyrimidin-5(8H)-one is filtered off, washed with water and recrystallized from dimethylformamide, yield 2.8 g. (88%); m.p. >300°.

1. filtrationThe precipitate of 8-ethyl-2-methylsulfinyl-4H-pyrazolo[4',3':5,6]pyrido[3,4-e][1,2,4]triazolo[1,5-a]pyrimidin-5(8H)-one is filtered off
2. washwashed with water
3. customrecrystallized from dimethylformamide, yield 2.8 g