![](/CAS/20180703/GIF/1228351-47-0.gif)
5-oxo-4,5-dihydro-pyrazolo[1,5-a]pyrimidine-2-carboxylic acid methyl ester synthesis
- Product Name:5-oxo-4,5-dihydro-pyrazolo[1,5-a]pyrimidine-2-carboxylic acid methyl ester
- CAS Number:1228351-47-0
- Molecular formula:C8H7N3O3
- Molecular Weight:193.16
![1H-Pyrazole-3-carboxylicacid,5-amino-,methylester(9CI)](/CAS/20180808/GIF/632365-54-9.gif)
632365-54-9
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$27.00/100mg
![Methyl propiolate](/CAS/GIF/922-67-8.gif)
922-67-8
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$6.00/1g
![5-oxo-4,5-dihydro-pyrazolo[1,5-a]pyrimidine-2-carboxylic acid methyl ester](/CAS/20180703/GIF/1228351-47-0.gif)
1228351-47-0
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Yield:1228351-47-0 29%
Reaction Conditions:
in 1,4-dioxane at 90; for 16 h;Inert atmosphere;
Steps:
3 Step-3: methyl 5-oxo-4,5-dihydropyrazolo[l,5-a]pyrimidine-2-carboxylate(A61)
To a stirred solution of methyl 3-amino-lH-pyrazole-5-carboxylate(A60, 22.0 g, 124.92 mmol) in l,4-dioxane(440 mL) was added methyl propiolate(13.30 mL, 149.90 mmol) under N2 atmosphere and the reaction mixture was stirred at 90 °C for 16 h. After completion of reaction mixture, the solvent was concentrated to dryness. The residue was purified by column chromatography using silica gel(100-200 mesh) 0-50% EtOAc/n-Hexnes as the eluent to afford methyl 5-oxo-4,5-dihydropyrazolo[l,5-a]pyrimidine-2-carboxylate A61 as a yellow solid. Yield: 7.0 g(29%) LC-MS(ES) m/z : 194.13[M+H]+.
References:
WO2019/102494,2019,A1 Location in patent:Paragraph 000215