1-Benzyl-5-nitro-1H-indazole → 1-(Phenylmethyl)-1H-indazol-5-amine

Participants

Reaction Conditions

Reaction Steps

A 500 mL Parr hydrogenator bottle was charged with 1-benzyl-5-nitroindazole (30.4 g, 120 mmol), absolute ethanol (240 mL) and 5% platinum on carbon (1.5 g, 50% wet). The bottle was placed on a Parr hydrogenation apparatus, the bottle pressurized with hydrogen to 50 psi and the bottle shook until the uptake of hydrogen ceased. The contents of the bottle were then transferred to a 1 L round bottomed flask, warmed to approximately 60° C. under nitrogen and rapidly filtered through a celite pad. The filter cake was washed with ethanol (100 mL). Water (250 mL) was then added to the filtrate and the resulting suspension stirred for 4 hours in an ice bath. The resulting solids were isolated by filtration, and the solids dried on the pump for 1 h. Three additional reduction runs were carried out under identical conditions. The four separate batches of material were then combined to give 87.4 g of crude material, which was re-crystallized from ethyl acetate (900 mL). Filtration and drying under reduced pressure (1 mmHg) afforded 65.0 g (59%) of the title compound as a light yellow solid.

Provenance & Evidence