5-Chloropyrazolo[1,5-a]pyrimidin-7(1H)-one synthesis

Yield:99898-84-7 100%

Reaction Conditions:

with sodium hydroxide in water at 90; for 0.5 h;

Steps:

Preparation of key intermediates a1-a4:

The raw material 5,7-dichloropyrazolo[1,5-a]pyrimidine a1-1 (53.2 mmol, 10 g) was dissolved in 30 mL of 1N NaOH aqueous solution, and the temperature was raised to 90° C. for 0.5 hours to stop the reaction.Cool to room temperature, slowly add 1N hydrochloric acid solution to adjust pH to 7, extract with dichloromethane, and dry over anhydrous Na₂SO₄to obtain intermediate a1-2 (9 g, quantitative yield)

References:

WO2022/12484,2022,A1 Location in patent:Page/Page column 30