4-Toluenesulfonyl chloride → 3-[4-amino-2-ethyl-1-(2-hydroxy-2-methylpropyl)-1H-imidazo[4,5-c]quinolin-7-yl]-N,N-dimethylpropanamide

Participants

Reaction Steps

To a stirring solution of crude 3-[2-ethyl-1-(2-hydroxy-2-methylpropyl)-1H-imidazo[4,5-c]quinolin-7-yl]-N,N-dimethylpropanamide, (1.2 g, 3.3 mmol) in dichloromethane (75 mL) was added 3-chloroperoxybenzoic acid (60% pure, 941 mg, 3.6 mmol). After 18 hours concentrated ammonium hydroxide (50 mL) was added and the reaction was vigorously stirred for 10 minutes. p-Toluenesulfonyl chloride (690 mg, 3.6 mmol) was then added in one portion and the reaction was stirred for one hour. The fractions were separated and the aqueous fraction was extracted with chloroform (3×50 mL). The combined organic fractions were concentrated under reduced pressure. Purification of the residue by chromatography using a HORIZON HPFC system (silica cartridge, eluting with 0-6% gradient of methanol in dichloromethane) followed by recrystallization from acetonitrile provided 651 mg of 3-[4-amino-2-ethyl-1-(2-hydroxy-2-methylpropyl)-1H-imidazo[4,5-c]quinolin-7-yl]-N,N-dimethylpropanamide as an off-white solid, mp 234-237° C.

Provenance & Evidence