Sulfuric Acid → HCID 136398804, compound

Participants

Reaction Steps

3-Amino-2-(2-hydroxyethyl)-6-(1,1-dimethylethyl)-2,5-dihydropyrazolo[3,4-d]pyrimidin-4-one (5 g) prepared as in Example 52 was added to concentrated sulphuric acid (10 ml). The solution was kept at 130°-135° C. for 3 hours, then cooled and poured onto ice (30 g). The precipitate which formed was filtered off, water washed and dissolved in 2 M sodium hydroxide solution. A trace of solid was filtered off, and the filtrate was acidified with concentrated hydrochloric acid to re-precipitate the title compound (4.4 g), m.p. 307°-309° C. decomp.

Provenance & Evidence