Ethyl 6-iodo-4-oxo-1-(pyrrolidin-3-ylmethyl)-1,4-dihydroquinoline-3-carboxylate hydrochloride (Intermediate 126, 500 mg, 1.08 mmol) was suspended in dimethyl formamide (3 mL) then tetrahydrofurfuryl chloride (1 mL) and potassium carbonate powder (400 mg, 22.2 mmol) were added. The reaction was stirred at 70° C. for 36 h. Water (15 mL) was added and the suspension was extracted with ethyl acetate (3×10 mL). The organic phases were combined, dried over sodium sulfate, and the solvent was removed in vacuo. The residue was chromatographed on a 4 g Analogix column using 0-10% methanol in dichloromethane. The solid was then dried in a vacuum oven at 50° C. for 18 h to give 181 mg (32% yield) of ethyl 6-iodo-4-oxo-1-((1-((tetrahydrofuran-2-yl)methyl)pyrrolidin-3-yl)methyl)-1,4-dihydroquinoline-3-carboxylate as an off white solid.
