Cesium carbonate → allyl 2-amino-5-oxo-4H-pyrazolo[1,5-a]pyrimidine-3-carboxylate

To a mixture of allyl 3,5-diamino-1H-pyrazole-4-carboxylate 3 (1 g, 5.489 mmol) and Cs2CO3 (2.504 g, 7.685 mmol) in EtOH (10 mL) was added methyl prop-2-ynoate (553.8 mg, 586.0 μL, 6.587 mmol), dropwise, over 15 minutes. The reaction mixture was stirred overnight at room temperature. The deep red reaction mixture was then filtered, washing through with a small amount of ethanol. The filtrate was cooled on an ice-bath and ether (100 ml) was slowly added; the mixture stirred at 0° C. for 20 mins. A yellow solid precipitated out of solution and was filtered off to afford a solid which was triturated in ether and filtered (3 cycles) to yield pure product as a yellow solid (yield 54%) LC-MS (M+H)+=235.1

1. customThe deep red reaction mixture
2. filtrationwas then filtered
3. washwashing through with a small amount of ethanol
4. temperatureThe filtrate was cooled on an ice-bath
5. additionether (100 ml) was slowly added
6. stirringthe mixture stirred at 0° C. for 20 mins
7. customA yellow solid precipitated out of solution
8. filtrationwas filtered off
9. customto afford a solid which
10. customwas triturated in ether
11. filtrationfiltered (3 cycles)

ORD record

ord-d2e46abcdb15466c9c26a103e2a2f831

Source dataset

uspto-grants-2015_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08969360B2