Potassium Carbonate → 2-(benzyloxy)-5-(6-cyclopropylpyridin-2-yl)-6,7-dihydropyrazolo[1,5-a]pyrazin-4(5H)-one

Participants

Reaction Conditions

Reaction Steps

Tetrakis(triphenylphosphine)palladium (0) (14.5 mg, 0.013 mmol) was added to a stirred suspension of 2-(benzyloxy)-5-(6-bromopyridin-2-yl)-6,7-dihydropyrazolo[1,5-a]pyrazin-4(5H)-one (0.1 g, 0.25 mmol), cyclopropylboronic acid (0.043 g, 0.5 mmol) and K2CO3 (0.104 g, 0.013 mmol) in a mixture of 1,4-dioxane (1 mL) and DMF (1 mL). The mixture was stirred at 150° C. for 15 minutes under microwave irradiation. The mixture was diluted with water and extracted with AcOEt. The organic layer was separated, washed with a saturated solution of NaCl, dried (Na2SO4), filtered and the solvents evaporated in vacuo. The crude product was purified by flash column chromatography (silica; AcOEt in DCM 0/100 to 20/80). The desired fractions were collected, the solvents evaporated in vacuo and the residue triturated with DIPE to yield 2-(benzyloxy)-5-(6-cyclopropylpyridin-2-yl)-6,7-dihydropyrazolo[1,5-a]pyrazin-4(5H)-one (41 mg, 45% yield) as a pale yellow solid. C21H20N4O2. 1H NMR (500 MHz, CDCl3) δ ppm 0.92-1.03 (m, 4H), 1.97-2.05 (m, 1H), 4.31 (dd, J=6.6, 5.2 Hz, 2H), 4.50 (dd, J=6.9, 5.2 Hz, 2H), 5.23 (s, 2H), 6.37 (s, 1H), 6.99 (d, J=6.9 Hz, 1H), 7.31-7.36 (m, 1H), 7.36-7.42 (m, 2H), 7.46 (d, J=7.2 Hz, 2H), 7.57 (t, J=7.9 Hz, 1H), 7.76 (dd, J=8.4, 0.6 Hz, 1H).

Provenance & Evidence