1,4-Diazabicyclo(3.2.2)nonane → 2-(1,4-Diaza-bicyclo[3.2.2]non-4-yl)-benzoimidazole-1-carboxylic acid tert-butyl ester

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Reaction Steps

2-Chloro-benzoimidazole-1-carboxylic acid tert-butyl ester (333 mg, 1.32 mmol), 1,4-diazabicyclo[3.2.2]nonane (57%, 195 mg, 0.88 mmol), tris(dibenzylideneacetone)dipalladium (28 mg, 0.031 mmol), racemic-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (58 mg, 0.093 mmol), sodium tert-butoxide (208 mg, 2.17 mmol) and toluene (1.55 mL) were added to a flame dried round bottom flask purged with nitrogen. The mixture was placed in an oil bath at 80° C. for 18 h and then cooled to RT. The mixture was filtered through a pad of celite and washed with chloroform and methanol. The filtrate was concentrated and the residue was purified by chromatography (Biotage, 12M) eluting with 8% methanol in chloroform with 20 drops of NH4OH per liter of eluent to afford 104 mg (34%) of 2-(1,4-diaza-bicyclo[3.2.2]non-4-yl)-benzoimidazole-1-carboxylic acid tert-butyl ester: MS (Cl) m/z 343.1 (M+1).

Provenance & Evidence