Ethyl Acrylate → ethyl (2E)-3-[4-amino-2-ethyl-1-(tetrahydro-2H-pyran-4-ylmethyl)-1H-imidazo[4,5-c]quinolin-7-yl]prop-2-enoate

Participants

Reaction Conditions

Reaction Steps

A thick walled glass vessel, equipped with a stir bar, was charged with a warmed solution of 7-bromo-2-ethyl-1-(tetrahydro-2H-pyran-4-ylmethyl)-1H-imidazo[4,5-c]quinolin-4-amine (2.5 g, 6.42 mmol) in N,N-dimethylformamide (50 mL). To the solution was added in succession, a solution of palladium acetate (144 mg, 0.642 mmol) and tri-ortho-tolylphosphine (390 mg, 1.28 mmol) in N,N-dimethylformamide (5 mL), triethylamine (2.7 mL) and a solution of ethyl acrylate (0.77 g, 7.7 mmol) in N,N-dimethylformamide (2 mL). The reaction mixture was purged with nitrogen. The vessel was sealed and heated at 120° C. for 18 hours. The reaction was cooled to ambient temperature and then concentrated to dryness under reduced pressure. The resulting solid was dissolved in dichloromethane (150 mL) and washed with saturated aqueous potassium carbonate (100 mL). The fractions were separated and the organic fraction was concentrated to dryness under reduced pressure. The resulting off-white solid was purified by chromatography using a HORIZON HPFC system (silica cartridge, 0-15% CMA/chloroform). A final recrystallization from acetonitrile provided 1.9 g of ethyl (2E)-3-[4-amino-2-ethyl-1-(tetrahydro-2H-pyran-4-ylmethyl)-1H-imidazo[4,5-c]quinolin-7-yl]prop-2-enoate as an off-white crystalline solid, mp 209-210° C.

Provenance & Evidence