Nicotinic acid N-oxide is an organic compound with the formula (HO2C)C5H4NO. It is the N-oxide of nicotinic acid ((HO2C)C5H4N). It is prepared by oxidation of nicotinic acid or the hydrolysis of 3-cyanopyridine N-oxide. The compound is a precursor to the popular drugs niflumic acid and pranoprofen.