Pyridine → Ammonia methanol

Participants

Reaction Steps

Combine 2-chloro-1-(2-ethoxyethyl)-1H-benzimidazole (12.2 g, 54.2 mmol) and [1,4]diazepane (11.34 g, 113 mmol), 1,8-diazabicyclo[5.4.0]undec-7-ene (9 mL), and pyridine (90 mL). Heat to reflux. After 18 hours, cool to ambient temperature and evaporate in vacuo to give a residue. Partition the residue between aqueous 1 M sodium hydroxide solution and ethyl acetate. Separate the layers and extract the aqueous layer two times with ethyl acetate. Combine the organic layers, dry over Na2SO4, filter, and evaporate in vacuo to give a residue. Chromatograph the residue on silica gel eluting sequentially with 30% methanol/ethyl acetate and then 2% concentrated aqueous ammonia/methanol to give the title compound: Rf =0.26 (silica gel, 2% concentrated aqueous ammonia/methanol).

Provenance & Evidence