Trifluoroacetic acid → HCID 57657231, compound

Participants

Reaction Steps

A glass Parr vessel was charged with 10% palladium on carbon (1 g), methanol (50 mL), 3-[4-amino-2-ethyl-1-(tetrahydro-2H-pyran-4-ylmethyl)-1H-imidazo[4,5-c]quinolin-7-yl]prop-2-enenitrile (4.0 g, 11.1 mmol) and trifluoroacetic acid (6.3 g, 55 mmol). The vessel was evacuated, charged with hydrogen gas (40 psi, 2.8×105 Pa) and shaken for approximately 18 hours. The mixture was filtered and concentrated under reduced pressure to a yellow oil. The oil was dissolved in 10% aqueous hydrochloric acid and stirred for 18 hours. Chloroform (100 mL) was added followed by slow addition of potassium carbonate until the pH equaled 11. The fractions were separated and the aqueous fraction was extracted with chloroform (4×50 mL). The combined organic fractions were sequentially dried (MgSO4), filtered, and concentrated under reduced pressure. Recrystallization from acetonitrile provided 3.55 g of the desired product as a white solid. A small amount of this material was further purified by chromatography using a HORIZON HPFC system (silica cartridge, eluting with a CMA:chloroform gradient, 0-30% CMA over 1000 mL followed by 30% CMA over 1000 mL). A final recrystallization from acetonitrile provided 7-(3-aminopropyl)-2-ethyl-1-(tetrahydro-2H-pyran-4-ylmethyl)-1H-imidazo[4,5-c]quinolin-4-amine as a white solid, mp 217-220° C.

Provenance & Evidence