Triethylamine → tert-butyl {4-[7-benzyloxy-1-(2-phenoxyethyl)-1H-imidazo[4,5-c]quinolin-2-yl]butyl}carbamate

Participants

Reaction Steps

Under a nitrogen atmosphere, a solution of 5-(tert-butoxycarbonylamino)valeric acid (1.50 g, 6.91 mmol) in dichloroethane (30 mL) was cooled to −25° C. Triethylamine (2.40 mL, 17.2 mmol) and pivaloyl chloride (0.85 mL, 6.91 mmol) were added, and the reaction was stirred for three hours, during which time the temperature rose to −10° C. 7-Benzyloxy-N4-(2-phenoxyethyl)quinoline-3,4-diamine (0.850 g, 2.20 mmol), prepared as described in Parts A-B of Example 46, was added in one portion followed by a small scoop of 4-dimethylaminopyridine. The reaction was allowed to warm to room temperature and stirred overnight and then heated at reflux for three hours. The reaction solution was washed with saturated sodium bicarbonate, water (2×), and brine, dried over sodium sulfate, filtered, and concentrated under reduced pressure. The crude product was purified by column chromatography on silica gel (eluting with sequentially with 98:2 and 95:5 chloroform:methanol) to yield a solid. The solid was treated with diethyl ether and concentrated under reduced pressure to provide 1.03 g of tert-butyl {4-[7-benzyloxy-1-(2-phenoxyethyl)-1H-imidazo[4,5-c]quinolin-2-yl]butyl}carbamate as a white powder.

Provenance & Evidence