Potassium Phosphate, Tribasic → 2-[1-(2,2-dimethylpropyl)-3-methyl-2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-5-yl]-4-hydroxybenzonitrile

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Reaction Steps

To a solution of [1-(2,2-dimethylpropyl)-3-methyl-2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-5-yl]boronic acid (16-1, 500 mg, 1.90 mmol) in anhydrous THF (15 ml) was added a solution of Potassium phosphate tribasic (807 mg, 3.80 mmol, 2.0 equiv) dissolved in water (2 ml). This mixture was treated with 2-chloro-4-hydroxybenzonitrile (409 mg, 2.66 mmol, 1.40 equiv), deoxygenated, then charged with Pd(OAc)2 (21 mg, 0.10 mmol, 0.05 equiv) and S-Phos (78 mg, 0.19 mmol, 0.10 equiv). The resulting dark mixture was irradiated in a microwave at 125° C. for 15 min. The reaction was 75% complete by LC/MS, so more 2-chloro-4-hydroxybenzonitrile (405 mg, 2.66 mmol, 1.40 equiv), Pd(OAc)2 (21 mg, 0.10 mmol, 0.05 equiv) and S-Phos (78 mg, 0.19 mmol, 0.10 equiv) were introduced, and the reaction mixture was irradiated at 140° C. for 25 min. The completed reaction was partitioned between EtOAc (3×75 ml) and saturated aqueous NaHCO3 (80 ml) and the combined organic layers were dried over MgSO4 and concentrated. The crude oil was purified via flash column chromatography (SiO2: 100% Hex to 50/50 Hex/EtOAc) which afforded the title compound, 2-[1-(2,2-dimethylpropyl)-3-methyl-2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-5-yl]-4-hydroxybenzonitrile (16-2), as a yellow solid-oil. LRMS m/z: Calc'd for C19H20N4O2 (M+H) 337.3. found 337.0.

Provenance & Evidence