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

Participants

Reaction Steps

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

Provenance & Evidence