Acetic Anhydride → HCID 135603558, compound

Participants

Reaction Steps

3,5-Diamino-1-phenylpyrazole-4-carboxamide (10.8 g) prepared as in Example 58 was heated with acetic acid (15 ml) and acetic anhydride (5.1 g) for 16 hours. The solution was poured into 2 M sodium hydroxide solution (200 ml) and a trace of solid was filtered off. The filtrate was adjusted to pH=7 with concentrated hydrochloric acid to precipitate 3-amino-2-phenyl-6-methyl-2,5-dihydropyrazolo[3,4-d]pyrimidin-4-one (6.1 g) which was recrystallised from 2-methoxyethanol (3.6 g yield), m.p. 279°-281° C.

Provenance & Evidence