Dimethyl Sulfoxide → 6-[2-(Pyridin-2-yl)-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazol-3-yl]-pyrazolo[1,5-a]pyrimidine

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Reaction Steps

To a microwave tube, add 6-bromo-pyrazolo[1,5-a]pyrimidine (0.175 g, 0.884 mmol), 2-(pyridin-2-yl)-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazole-3-boronic acid (0.25 g, 1.09 mmol), tetrakis(triphenylphosphine)palladium(0) (31 mg, 0.027 mmol), 2M aqueous potassium carbonate (0.5 mL, 1.0 mmol) and dimethylsulfoxide (1.5 mL). Irradiate the reaction in a microwave reactor set at 110° C., 50 Watts, 10 min with external cooling. Dilute the reaction mixture with diethyl ether (250 mL) and extract the product into 0.1M aqueous hydrochloric acid (450 mL). Make the aqueous solution basic by adding 5M aqueous sodium hydroxide (25 mL) and extract with dichloromethane (300 mL). Filter the organic layer and concentrate under reduced pressure. Recrystallize the resulting solid from ethyl acetate, filter, rinse with ethyl acetate, and dry at 100° C. under vacuum to obtain 70 mg (26%) of the title compound as a tan solid. MS (electrospray, m/z) 302.9 (M+1).

Provenance & Evidence