Potassium Phosphate, Tribasic → 6-(4-Hydroxyphenyl)-1-(2-morpholinoethyl)-1H-imidazo[4,5-B]pyrazin-2(3H)-one

Participants

Reaction Steps

6-(4-Hydroxyphenyl)-1-(2-morpholinoethyl)-1H-imidazo[4,5-b]pyrazin-2(3H)-one hydrochloride. 6-Bromo-1-(2-morpholinoethyl)-1H-imidazo[4,5-b]pyrazin-2(3H)-one (300 mg, 0.95 mmol), [4-(N-methylaminocarbonyl)phenyl]boronic acid (205 mg, 1.15 mmol), dichloro[1,1′-bis(diphenylphosphino)ferrocene]palladium (II) dichloromethane (80 mg, 0.09 mmol) and potassium phosphate (805 mg, 3.8 mmol) in DMF (30 mL) and water (8 mL) were reacted according to General Procedure C. The product was purified by reverse-phase semi-preparatory HPLC (30-100% acetonitrile+0.1% TFA in H2O+0.1% TFA, over 30 min). The desired fractions were concentrated, treated with 4N hydrochloric acid in diethylether (few drops) and sonicated. This procedure was repeated twice more to provide 6-(4-hydroxyphenyl)-1-(2-morpholinoethyl)-1H-imidazo[4,5-b]pyrazin-2(3H)-one (67 mg, 16%) as a colorless solid hydrochloride salt. 1H NMR (400 MHz, CD3OD-d6) δ 8.38 (s, 1H), 8.84 (d, J=8.4, 2H), 7.44 (s, 1H), 7.39 (d, J=8.4, 2H), 4.45 (t, J=5.6, 2H); 4.07 (d, J=12.4, 2H), 3.82 (d, J=12.4, 2H), 3.69-3.64 (m, 4H); MS (ESI) m/z 342.15 [M+1]+.

Provenance & Evidence