Patent ID: 7687628

Claim:
A method of preparing an acid addition salt of formula (5) consisting of the step of hydrolyzing a 4-(arylmethyl)amino-1H-imidazo(4,5-c)quinoline of formula (4) with a strong acid, HX, wherein R 1 and R 2 are independently selected from the group consisting of hydrogen, C 1 -C 4 alkyl, C 3 -C 4 cycloalkyl, C 2 -C 4 alkenyl, and C 2 -C 4 alkynyl, each of R 5 , R 6 , R 7 , R 8 , and R 9 is hydrogen, and X − is a conjugate base of a strong acid, thereby forming an acid addition salt of formula (5), wherein at least one of R 1 and R 2 is hydrogen.