反应详情

The product of step (a) (1.0 g) was dissolved in concentrated sulphuric acid (1 ml) and stirred vigorously for 0.5 hours. The deep red solution was then poured into iced aqueous ammonia solution (100 ml), and the precipitate filtered to give the title compound, 0.5 g, as an orange powder, mp 265°-270° C. (decomposes).

1. filtrationthe precipitate filtered