Sodium borohydride → HCID 57545331, compound

Participants

Reaction Steps

Nickel(II)chloride (0.044 g, 0.34 mmol) was added to a solution of 1-(2-methylpropyl)-7-(4-nitrophenoxy)-2-propyl-1H-imidazo[4,5-c]quinolin-4-amine (0.436 g 1.04 mmol), prepared as described in Example 35, in 20:80 dichloromethane methanol (30 mL). Sodium borohydride (0.300 g) was added in small portions to the resulting solution, and the reaction was stirred for 25 minutes. A solid formed in the reaction and was removed by filtration, and the filtrate was concentrated under reduced pressure. The residue was dissolved in chloroform, and the resulting solution was washed with water. The organic solution was stirred with AMBERLITE IRA-756 ion exchange resin for 30 minutes, and the resin was then removed by filtration. The filtrate was concentrated under reduced pressure to provide a brown oil, which was purified by flash chromatography using a 10 g silica gel cartridge (RediSep, ISCO, 230-400 mesh) attached to a gradient pump system, 254 nm UV detector and fraction collector (ISCO COMBIFLASH Sg100c system). The column was equilibrated with 1% methanol in dichloromethane and the reaction mixture was injected onto the column. The mixture was eluted at 35 mL/minute, with a linear gradient program consisting of 1% methanol/dichloromethane to 5% methanol/dichloromethane over five minutes and holding at 5% methanol/dichloromethane to elute the desired compound. Fractions were examined by TLC and those containing the desired compound were combined and concentrated. The product was then recrystallized from acetonitrile to yield 0.242 g of 7-(4-aminophenoxy)-1-(2-methylpropyl)-2-propyl-1H-imidazo[4,5-c]quinolin-4-amine as a tan, crystalline solid, mp 190-191° C.

Provenance & Evidence