Cesium carbonate → 6-(2-chloropyrimidin-4-yl)-2-(2-trimethylsilanylethoxymethyl)-4-[1-(2-trimethylsilanylethoxymethyl)-1H-benzimidazol-2-yl]-2H-pyridazin-3-one

Participants

Reaction Conditions

Reaction Steps

1.32 g of 6-oxo-1-(2-trimethylsilanylethoxymethyl)-5-[1-(2-trimethylsilanylethoxy-methyl)-1H-benzimidazol-2-yl]-1,6-dihydropyridazine-3-boronic acid, 583 mg of 2,4-dichlorpyrimidine and 3,3 g of cesium carbonate are dissolved in 17 ml of a 1:4 mixture of water and dioxane, and argon is passed through the solution for degassing. After addition of 125 mg of (1,1′-bis(diphenyl-phosphine)ferrocene)palladium(II) chloride-dichloromethane complex, the solution is stirred at 97° C. for 3 hours. For workup, it is diluted with 50 ml of water and extracted several times with ethyl acetate. The combined organic phases are dried using a silica gel cartridge, and the solvent is distilled off. The crude product is purified by preparative RP-HPLC (0-100% acetonitrile in water (+0.01% trifluoroacetic acid)).

Provenance & Evidence