Pyridine-4-carboxylic acid N-oxide (CAS NO.13602-12-5) is also named as 4-Pyridinecarboxylic acid 1-oxide ; NSC 63044 ; 4-Pyridinecarboxylic acid, 1-oxide ; Pyridin-N-oxide-4-carboxylic acid ; Isonicotinic acid N-oxide ; Pyridine-4-carboxylic acid 1-oxide . Pyridine-4-carboxylic acid N-oxide (CAS NO.13602-12-5) is white to beige or yellow crystalline powder.