2(1H)-Pyrimidinone, hydrazone (9CI)

1722-12-9

7504-94-1

The general procedure for the synthesis of 2-hydrazinopyrimidine from 2-chloropyrimidine was as follows: first, 2-chloropyrimidine (1.145 g, 20 mmol) was dissolved in ethanol (30 mL). Subsequently, an excess of 85% hydrazine hydrate (6 mL) was slowly added to the above solution under continuous stirring. The reaction mixture gradually changed to a bright yellow solution and white needle-like crystals were precipitated after 2 hours. The crystals were collected by filtration and recrystallized in ethanol to afford the target product 2-hydrazinopyrimidine in 80% yield. Next, 3-methylsalicylaldehyde (1.36 g, 10 mmol) was added to an ethanolic solution (30 mL) of 2-hydrazinopyrimidine (1.10 g, 10 mmol) and the formation of a pale yellow precipitate was immediately observed. After refluxing the reaction mixture for 3 h, the precipitate was filtered and collected and washed with ethanol to give a final light yellow H2mphp powder in 95% yield.