反应详情

1,3-Di-n-butyl-8-nitro xanthine from Example 1 (8.5 g) was suspended in concentrated hydrochloric acid (85 ml) and then treated at room temperature with tin powder (14.5 g) in small portions. After stirring for 10 minutes the yellow colour of the suspension disappeared. Thereafter the precipitate was filtered off and recrystallised twice from ethanol. The product formed colourless crystals, yield 5.5 g (63%) m.pt >250° C.

1. filtrationThereafter the precipitate was filtered off
2. customrecrystallised twice from ethanol
3. customThe product formed colourless crystals, yield 5.5 g (63%) m.pt >250° C.