Sodium Hydroxide → 4-(4-amino-2-propyl-2H-pyrazolo[3,4-c]quinolin-1-yl)butan-1-ol

Participants

Reaction Steps

A solution of di(tert-butyl) 1-(4-hydroxybutyl)-2-propyl-2H-pyrazolo[3,4-c]quinolin-4-ylimidodicarbonate (prepared as described in Parts A-C of Example 57, 0.507 g, 1.02 mmol) in 6 M HCl in ethanol (5 mL) was heated at 60° C. for 1.5 hours. The solution was allowed to cool to room temperature, and then was concentrated under reduced pressure to yield an oil. The oil was triturated with ether to obtain a solid that was isolated by filtration. The solid was dissolved in methanol and the solution was adjusted to approximately pH 14 with 50% aqueous sodium hydroxide. The solution was concentrated under reduced pressure and the crude product was purified by chromatography (silica gel, elution with 5% CMA in chloroform) followed by crystallization from hexanes/ethyl acetate to provide 0.084 g of 4-(4-amino-2-propyl-2H-pyrazolo[3,4-c]quinolin-1-yl)butan-1-ol as white needles, mp 135.0-136.0° C.

Provenance & Evidence