2-(Dimethylamino)ethanol → Allyl 2-amino-5-(2-(dimethylamino)ethoxy)pyrazolo[1,5-a]pyrimidine-3-carboxylate

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Reaction Steps

To a mixture of allyl 2-amino-5-oxo-4H-pyrazolo[1,5-a]pyrimidine-3-carboxylate (1 g, 4.270 mmol) in MeCN (15 mL) was added 2,3,4,6,7,8,9,10-octahydropyrimido[1,2-a]azepine (975.1 mg, 957.9 μL, 6.405 mmol) and benzotriazol-1-yloxy(tripyrrolidin-1-yl)phosphonium (Phosphorus Hexafluoride Ion) (2.666 g, 5.124 mmol). After 5 minutes, 2-dimethylaminoethanol (3.806 g, 4.291 mL, 42.70 mmol) and cesium carbonate (5 g) were added and the mixture was stirred at room temperature for 30 minutes, followed by heating to 50° C. for 30 minutes. After cooling to room temperature the mixture was filtered and the solid washed with acetonitrile. The combined filtrate was concentrated in vacuo to an orange oil and purified by column chromatography using 4% MeOH/DCM as eluent to provide 4b (yield 35%) LC-MS (M+H)+=306.2.

Provenance & Evidence