反应详情

A mixture of 1.984 g of N,N-dimethyl4-bromobenzenesulfonamide, 2.1 g of bis-(pinacolato)-diboron, 0.125 g of 1,1′-bis-(diphenylphosphino)-ferrocene, 0.165 g of [1,1′-bis(diphenyl-phosphino)ferrocene]palladium-dichloride (complex with CH2Cl2), 2.21 g of potassium acetate in 50 ml of degassed dioxane are heated to reflux under N2 for 16 hours. To the resulting mixture 40 ml of degassed dioxane, 2.14 g of 2-[2-(4-methoxypyridin-2-yl)ethyl]-6-iodo-3H-imidazo[4,5-b]pyridine (starting material A1), 0.65 g of tetrakis(triphenylphos-phine)-palladium(0) and a solution of 1.56 g of potassium carbonate and 0.48 g of lithium chloride in 40 ml of degassed water are added under N2. The mixture is heated to reflux under N2 for 7 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 30-15:1). Concentration of the chromatographically pure fractions, crystallization from methanol and recrystallization from ethylacetate gives 2.01 g of the title compound as a solid of m.p. 217-218° C. The mass spectrum shows the molecular peak MH+ at 438.3 Da.

1. temperatureare heated
2. temperatureto reflux under N2 for 16 hours
3. temperatureThe mixture is heated
4. temperatureto reflux under N2 for 7 hours
5. temperatureafter cooling
6. extractionis extracted three times with dichloromethane
7. dry with materialThe combined organic phases are dried over sodium sulfate
8. concentrationconcentrated
9. customthe residue is chromatographed on a silica gel column (dichloromethane/methanol 30-15:1)
10. customConcentration of the chromatographically pure fractions, crystallization
11. customfrom methanol and recrystallization from ethylacetate