2-benzyl-1-(2-methylpropyl)-2H-pyrazolo[3,4-c]quinolin-4-amine → 1-(2-methylpropyl)-2H-pyrazolo[3,4-c]quinolin-4-amine

Participants

Reaction Conditions

Reaction Steps

Hydrogen bromide (10 mL of 30% by weight in acetic acid) and 2-benzyl-1-(2-methylpropyl)-2H-pyrazolo[3,4-c]quinolin-4-amine (0.75 g, 2.27 mmol) were combined in a TEFLON-lined Parr vessel and heated at 150° C. for 24 hours and then allowed to cool to ambient temperature over five hours. The reaction was filtered to remove a solid, and the filtrate was adjusted to pH 7 with the addition of 50% sodium hydroxide and 2M aqueous sodium carbonate. A precipitate formed and was isolated by filtration, washed with water, and air-dried. The solid was purified by chromatography on a HORIZON HPFC system (25+M cartridge, eluting with chloroform/CMA in a gradient from 80:20 to 40:60) followed by recrystallization from acetonitrile (19 mL/g) and a small amount of methanol. The crystals were isolated by filtration, washed with acetonitrile, and dried for 36 hours in a vacuum oven at 65° C. to provide 139 mg of 1-(2-methylpropyl)-2H-pyrazolo[3,4-c]quinolin-4-amine as small, pale orange needles, mp 248-249° C.

Provenance & Evidence