3-Pyridinylboronic acid → dimethyl 5-[4-amino-2-ethoxymethyl-7-(pyridin-3-yl)-1H-imidazo[4,5-c]quinolin-1-yl]pentane-1-sulfonamide

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Reaction Steps

Dimethyl 5-(4-amino-7-bromo-2-ethoxymethyl-1H-imidazo[4,5-c]quinolin-1-yl)pentane-1-sulfonamide (0.26 g, 0.53 mmol) and pyridine-3-boronic acid (0.78 g, 0.63 mmol) were coupled according to the method described in Part J of Example 1. The reaction was heated at 100° C. for 31 hours, at which time additional palladium acetate (0.002 equivalent) was added. Heating was resumed for 14 hours, and then additional pyridine-3-boronic acid (0.3 equivalent) was added. The reaction was heated for another 22 hours. The work-up procedure used in Part F of Examples 125-135 was followed. The crude product was purified twice by HPFC (eluting with chloroform:CMA in a gradient from 100:0 to 80:20) and then triturated with ethyl acetate and isolated by filtration. The product was finally recrystallized from isopropanol, isolated by filtration, and dried for eight hours under high vacuum at 100° C. to provide 0.090 g of dimethyl 5-[4-amino-2-ethoxymethyl-7-(pyridin-3-yl)-1H-imidazo[4,5-c]quinolin-1-yl]pentane-1-sulfonamide as a white powder, mp 159-160° C.

Provenance & Evidence