1-Benzyl-1H-pyrazol-5-amine → 1-benzyl-N-(tetrahydro-2H-pyran-4-yl)-1H-pyrazol-5-amine

Participants

Reaction Steps

To a solution of 1-benzyl-1H-pyrazol-5-amine (2.09 g) in acetic acid (20 mL) was added tetrahydro-4H-pyran-4-one (1.25 g), and the mixture was stirred at room temperature for 30 min. After stirring, sodium triacetoxyborohydride (3.90 g) was added at room temperature, and the mixture was stirred overnight. Acetic acid was evaporated under reduced pressure and ethyl acetate and water were added to the residue. The mixture was neutralized with sodium hydrogen carbonate, and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with saturated brine, and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography to give the title compound as a pale-yellow oil (3.00 g, 97%).

Provenance & Evidence