Trifluoroacetic acid → HCID 57568677, compound

Participants

Reaction Steps

Trifluoroacetic acid (3 mL) was added slowly to a solution of tert-butyl 2-[4-({2-[2-(ethoxymethyl)-1H-imidazo[4,5-c]quinolin-1-yl]-1,1-dimethylethyl}amino)-4-oxobutanoyl]hydrazinecarboxylate (0.688 g, 1.34 mmol) in dichloromethane (7 mL). The solution was stirred for 2.5 hours, then was concentrated under reduced pressure. The trifluoroacetic acid salt of N-{2-[2-(ethoxymethyl)-1H-imidazo[4,5-c]quinolin-1-yl]-1,1-dimethylethyl}-4-hydrazino-4-oxobutanamide was applied to anion exchange resins, which were eluted with pyridine in methanol to provide N-{2-[2-(ethoxymethyl)-1H-imidazo[4,5-c]quinolin-1-yl]-1,1-dimethylethyl}-4-hydrazino-4-oxobutanamide as a free base, which was purified by HPFC on silica gel (gradient elution, 2-50% CMA in chloroform). The appropriate fractions were concentrated under reduced pressure to yield a foam that was heated under vacuum to afford 0.31 g of N-{2-[2-(ethoxymethyl)-1H-imidazo[4,5-c]quinolin-1-yl]-1,1-dimethylethyl}-4-hydrazino-4-oxobutanamide as a glassy solid.

Provenance & Evidence