Methyl Acrylate → Methyl(2E)-3-[4-amino-2-butyl-1-(2-methylpropyl)-1H-imidazo[4,5-c]quinolin-7-yl]prop-2-enoate

Participants

Reaction Conditions

Reaction Steps

A thick walled glass tube, equipped with stir bar, was charged with palladium (II) acetate (18 mg, 0.08 mmol), acetonitrile (2 mL), methyl acrylate (69 mg, 0.8 mmol), triethylamine (240 mg, 2.4 mmol), tri-o-tolylphosphine (49 mg, 0.16 mmol) and 7-bromo-2-butyl-1-(2-methylpropyl)-1H-imidazo[4,5-c]quinolin-4-amine (U.S. Patent Application Publication No. US 2004/0147543 Example 1, 300 mg, 0.8 mmol). The reaction mixture was purged with nitrogen and the tube was sealed and heated to 100° C. in an oil bath. The mixture became an amber homogeneous solution after approximately 5 minutes. The reaction was maintained at 100° C. for 32 hours and then concentrated to dryness. The reaction mixture was taken up in water and dichloromethane. Saturated aqueous potassium carbonate solution was added, adjusting to pH 11. The organic layer was separated and concentrated to a golden syrup. The crude product was purified by flash chromatography on silica gel (eluting with 5% methanol/dichloromethane). The resulting tan solid (230 mg) was recrystallized from acetonitrile to give 220 mg of Methyl(2E)-3-[4-amino-2-butyl-1-(2-methylpropyl)-1H-imidazo[4,5-c]quinolin-7-yl]prop-2-enoate as a pale gold solid, mp 193-194° C.

Provenance & Evidence