4-Toluenesulfonyl chloride → HCID 69507356, compound

Participants

Reaction Steps

3-Chloroperoxybenzoic acid (70% pure, 5.46 g, 22.16 mmol) (mCPBA) was added to a solution of 5-(2-butyl-1H-imidazo[4,5-c][1,5]naphthyridin-1-yl)pentan-2-one (3.44 g, 11.08 mmol, 1 eq) in chloroform (45 mL), and the reaction was stirred for one hour at ambient temperature and then cooled to 5° C. Ammonium hydroxide (10 mL) and p-toluenesulfonyl chloride (2.32 g, 12.19 mmol, 1.1 eq) were sequentially added and the reaction mixture was stirred at 5-10° C. for 1 hour, filtered, and then diluted with dichloromethane (100 mL) and saturated aqueous sodium bicarbonate (75 mL). The aqueous layer was extracted with dichloromethane (2×30 mL) and the combined organic solutions were dried over magnesium sulfate, filtered, and concentrated under reduced pressure to provide a brown oil. The material was triturated with acetonitrile to afford 1.65 g of 5-(4-amino-2-butyl-1H-imidazo[4,5-c][1,5]naphthyridin-1-yl)pentan-2-one. The filtrate from the trituration was purified by BIOTAGE HORIZON High-Performance Flash Chromatography (HPFC) instrument (eluting with chloroform/methanol/ammonium hydroxide (CMA) (80/18/2):chloroform ranging in ratios from 0:100 to 25:75) and subjected to trituration again in acetonitrile to produce an additional 0.240 g of material as an off-white powder, mp 168-169° C. Anal. calcd for C18H23N5O: C, 66.44; H, 7.12; N, 21.52. Found: C, 66.19; H, 7.08; N, 21.22.

Provenance & Evidence