5-Chloropyrazolo[1,5-a]pyrimidin-7(1H)-one synthesis
- Product Name:5-Chloropyrazolo[1,5-a]pyrimidin-7(1H)-one
- CAS Number:99898-84-7
- Molecular formula:C6H4ClN3O
- Molecular Weight:169.57
![5,7-DICHLOROPYRAZOLO[1,5-A]PYRIMIDINE](/CAS/GIF/57489-77-7.gif)
57489-77-7
99898-84-7
General procedure for the synthesis of 5-chloropyrazolo[1,5-a]pyrimidin-7(1H)-ones from 5,7-dichloropyrazolo[1,5-a]pyrimidines: 1 g of 5,7-dichloropyrazolo[1,5-a]pyrimidines was suspended in 25 mL of 1 N aqueous sodium hydroxide solution, heated to 90 °C and stirred for 0.5 h. The reaction was carried out by thin layer chromatography (TLC). The progress of the reaction was monitored by thin layer chromatography (TLC). After completion of the reaction, the reaction mixture was cooled to room temperature. The pH was adjusted to 2 with 1N HCl solution to form a suspension. 5-Chloropyrazolo[1,5-a]pyrimidin-7(1H)-one (0.9 g, 99% yield) was obtained by filtration after standing.
57489-77-7
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$13.00/100mg
99898-84-7
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$85.00/100mg
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