Hydrochloric Acid → TLR7/8 agonist 3

Participants

Reaction Steps

Tert-butyl 2-[4-amino-2-(ethoxymethyl)-1H-imidazo[4,5-c]quinolin-1-yl]-1,1-dimethylethylcarbamate (1.26 g, 3.05 mmol) was dissolved in 10 mL of EtOH and treated with 10 mL of 2 M HCl in EtOH. After heating at reflux for 2 hours, the reaction mixture was cooled and concentrated under reduced pressure. The resulting yellow solid was dissolved in 50 mL of H2O and extracted with CHCl3 (20 mL). The organic layer was discarded and the aqueous portion was made basic (pH˜12) by addition of concentrated NH4OH solution. This was then extracted with CHCl3 (4×20 mL) and the combined organic portions were dried with Na2SO4 and concentrated to give 1-(2-amino-2-methylpropyl)-2-(ethoxymethyl)-1H-imidazo[4,5-c]quinoline-4-amine (808 mg) as a light brown powder. m.p. 161.0-162.0° C.;

Provenance & Evidence