6-(((Phenylmethoxy)carbonyl)amino)hexanoic acid → HCID 68926476, compound

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Reaction Steps

To a solution of 6-(carbobenzyloxyamino) caproic acid (8.49 grams (g), 32.0 millimole (mmol)) in DMF (50 mL) at 0° C. was added N-hydroxysuccinimide and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC). After a short period, the solution was added to a 0° C. solution of 1-(2-amino-2-methylpropyl)-2-(ethoxymethyl)-1H-imidazo[4,5-c]quinolin-4-amine (prepared as described in U.S. Patent Publication No. 2004/0091491, 10 g, 32 mmol) in DMF (100 mL). The mixture was allowed to warm to room temperature and was stirred for 3 days. The solution was diluted with water (400 mL) and extracted with ethyl acetate (3×). The organic layers were combined and washed with water (2×) and brine. The organic layer was dried over sodium sulfate, filtered, and concentrated. The crude product was purified by HPFC on silica gel three times (gradient elution with CMA in chloroform) to provide 4.90 g of benzyl 6-({2-[4-amino-2-(ethoxymethyl)-1H-imidazo[4,5-c]quinolin-1-yl]-1,1-dimethylethyl}amino)-6-oxohexylcarbamate as a white foam.

Provenance & Evidence