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

Participants

Reaction Steps

4-Methoxybenzyl 4-(4-amino-7-bromo-2-ethoxymethyl-1H-imidazo[4,5-c]quinolin-1-yl)butane-1-sulfonamide (1.16 g, 2.0 mmol) and pyridine-3-boronic acid (0.30 g, 2.4 mmol) were coupled according to the method described in Part J of Example 1. The reaction was heated at reflux for 14 hours, at which time additional pyridine-3-boronic acid (0.3 equivalent) was added and the reaction was heated for an additional five hours. The work-up procedure used in Part F of Examples 125-135 was followed. The crude product was purified by column chromatography on silica gel (eluting with chloroform:CMA in a gradient from 100:0 to 80:20) and then triturated with methanol, isolated by filtration, and dried for 20 hours under high vacuum at 140° C. to provide 0.62 g of 4-methoxybenzyl 4-[4-amino-2-ethoxymethyl-7-(pyridin-3-yl)-1H-imidazo[4,5-c]quinolin-1-yl]butane-1-sulfonamide as a beige powder, mp 230-231.5° C.

Provenance & Evidence