Potassium Carbonate → 4-{2-[2-(4-Methoxypyridin-2-yl)ethyl]-3H-imidazo[4,5-b]pyridin-6-yl}-N-methyl-benzenesulfonamide

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Reaction Conditions

Reaction Steps

A mixture of 0.375 g of N-methyl-4-bromobenzenesulfonamide, 0.42 g of bis-(pinacolato)-diboron, 0.025 g of 1,1′-bis-(diphenylphosphino)-ferrocene, 0.033 g of [1,1′-bis(diphenylphosphino)-ferrocene]palladium-dichloride (complex with CH2Cl2), 0.442 g of potassium acetate in 6 ml of degassed dioxane are heated to 90° C. in a sealed tube under N2 for 16 hours. To the resulting mixture 5 ml of degassed dioxane, 0.371 g of 2-[2-(4-methoxypyridin-2-yl)ethyl]-6-iodo-3H-imidazo[4,5-b]pyridine (starting material A1), 0.113 g of tetrakis(triphenylphos-phine)-palladium(0) and a solution of 0.27 g of potassium carbonate and 0.083 g of lithium chloride in 5 ml of degassed water are added under N2. The tube is sealed again, the mixture is heated to 90° under N2 for 8 hours and, after cooling, addition of water and adjusting the pH to 7, it is extracted three times with dichloromethane. The combined organic phases are dried over sodium sulfate, concentrated and the residue is chromatographed on a silica gel column (dichloromethane/methanol 20-15:1). Concentration of the chromatographically pure fractions and crystallisation from ethyacetate gives 0.219 g of the title compound as a solid of m.p. 225-227° C. The mass spectrum shows the molecular peak MH+ at 424.3 Da.

Provenance & Evidence