2-Bromopropanedial → 5-Bromopyrazolo[3,4-b]pyridine

Participants

Reaction Steps

Dissolve 2-bromomalonaldehyde (Aldrich; 2.5 g, 16.5 mmol) and 3-aminopyrazole (Aldrich; 1.38 g, 16.5 mmol) in glacial acetic acid (25 mL) and reflux under nitrogen for 2 h. Concentrate under reduced pressure and dissolve the residue in absolute methanol (150 mL), vacuum filter through a pad of diatomaceous earth and concentrate under reduced pressure. Purify via chromatography (silica gel, hexane to 50% ethyl acetate/50% hexane) to obtain 365 mg (11%) of the title compound as a light yellow solid. TOF MS ES+ exact mass calculated for C6H5N3Br (p+H): m/z=197.9667, Found: 197.9674.

Provenance & Evidence